Shu - Te University

College of Management

Graduate School of Business Administration

Master

An Influence Factors Study on Job Satisfaction of Employees at

Hai Duong Power Company, Hai Duong Province, Vietnam

Student: Pham Tuan Ngoc

ID: s99733421

Advisor: Dr. Wang Jau Shyong

Co-Advisor: Dr. Sheng Jung Li

Dr. Nguyen Danh Nguyen

September, 2013

Shu-Te U

niversity

Graduate S

chool of

Business A

dministration

Thesis

An Influence F

actors Study on Job S

atisfaction of

Em

ployees at Hai D

uong Pow

er Com

pany, Hai D

uong P

rovince, Vietnam

ong Pow

er Com

pany, Hai D

uong P

rovince, Vietnam

Pham

Tuan N

gocS

eptember, 2013

An Influence Factors Study on Job Satisfaction of Employees at Hai

Duong Power Company, Hai Duong Province, Vietnam

Student: Pham Tuan Ngoc

ID: s99733421

Advisor: Dr. Wang Jau Shyong

Co-Advisor: Dr. Sheng Jung Li

Dr. Nguyen Danh Nguyen

A Thesis

Submitted to the

Graduate School of Business Administration

College of Management

Shu-Te University

In Partial Fulfillment of the Requirements

For the Degree of

Master of Science in

Business Administration

September, 2013

Shu-Te University

Graduate School of Business Administration

An Influence Factors Study on Job Satisfaction of Employees at Hai Duong

Power Company, Hai Duong Province, Vietnam

Student: Pham Tuan Ngoc

Advisor: Dr. Wang Jau Shyong Co-Advisor: Dr. Sheng Jung Li

Dr. Nguyen Danh Nguyen

Abstract

The main purpose of the study is to test the relationship between variables in JDI

model with general job satisfaction. The research results are obtained from actual

survey at Hai Duong Power Company with 200 employees. The research method in this

study is quantitative method with statistical techniques such as: testing by Cronbach

Alpha coefficient, explore factor analysis, correlation analysis and regression analysis.

The research results show that there are four in five factors in JDI model affecting job

satisfaction including: (1) work, (2) promotion opportunities; (3) co-workers, and (4)

supervisors. In demographic variables, the factor “age” has impact on the satisfaction

with job of employees. The study also suggests some solutions and recommendations

for company’s managers to improve job satisfaction of employees. And in the last, the

study points out limitations and directions for further researches in the same research

fields.

Key words: job satisfaction, JDI, power.

i

Acknowledgements

During the time of conducting this thesis, I have received many helps from many

people. Without these helps, I have probably not finished my dissertation, so I would

like to express my thanks to all of you.

I know that this project was not my individual achievement, but the result of many

people to whom I will be forever grateful. Of those, I would like to express my sincere

gratitude to my wife, who has been my cheer leader since high school. Her unwavering

support through this process could never be fully articulated. Her role was fundamental

in the mailing and scoring of the survey materials, and she contributed countless hours

to the completion of this project. She is, and always will be my rock.

Special thanks to Dr. Jau- Shyong Wang who has stuck with me from the

beginning of this journey, and always been there to share his expertise and guidance. I

would also like to thank the other members of my committee and my classmates. Each

of you has assisted in the development and review of this project, and I am thankful to

you all.

I would also like to thank my supervisor Dr. Nguyen for their on-going support

and for being flexible with my work schedule while I attended classes.

Finally, I want to say thanks very much for Dr. Jau-Shyong Wang, Dr. Sheng-

Jung Li, and Dr. Nguyen Danh Nguyen again with their advises and supported.

Special thanks for your help

ii

Table of Contents

Abstract..............................................................................................................................i

Acknowledgements...........................................................................................................ii

Table of Contents.............................................................................................................iii

List of Tables....................................................................................................................vi

List of Figures.................................................................................................................vii

Chapter 1 Introduction.......................................................................................................1

1.1 Research Background.......................................................................................1

1.2 Research Motivations........................................................................................4

1.3 Research Purposes............................................................................................4

1.4 Research Procedure...........................................................................................5

Chapter 2 Literature Review.............................................................................................7

2.1 Definition of job satisfaction............................................................................7

2.2 Theories of job satisfaction...............................................................................7

2.2.1 Maslow's hierarchy of needs...................................................................8

2.2.2 McClelland's achievement motivation theory.........................................9

2.2.3 Vroom’s Expectancy theory..................................................................10

2.2.4 Motivation theory..................................................................................10

2.3 Advantages of employee satisfaction..............................................................11

2.4 Factors affecting job satisfaction....................................................................12

2.4.1 Work.....................................................................................................12

2.4.2 Promotion opportunities........................................................................12

2.4.3 Supervisors............................................................................................13

2.4.4 Co-workers............................................................................................13

2.4.5 Salary.....................................................................................................14

2.5 The effects of job satisfaction.........................................................................14

2.5.1 Overall Performance..............................................................................14

2.5.2 Quitting the job......................................................................................15

2.5.3 Absence of work....................................................................................15

iii

Chapter 3 Research Methodology...................................................................................17

3.1 The population and research sample...............................................................17

3.2 Measurements.................................................................................................18

3.2.1 The reliability of JDI.............................................................................18

3.2.2 The validity of JDI.................................................................................19

3.2.3 Reasons for selecting JDI......................................................................19

3.3 Research model and hypotheses.....................................................................20

3.4 Scales for research variables and design of questionnaire..............................20

3.5 Data analysis...................................................................................................23

3.5.1. Descriptive statistics..............................................................................24

3.5.2. Scale verification...................................................................................24

3.5.3. Explore factor analysis..........................................................................24

3.5.4 Building regression function..................................................................25

3.5.5 Testing research hypotheses...................................................................25

Chapter 4 Research Results.............................................................................................26

4.1 Descriptive statistics.......................................................................................26

4.1.1 Gender...................................................................................................26

4.1.2 Age........................................................................................................26

4.1.3 Education level......................................................................................27

4.1.4 Work experience....................................................................................28

4.2 Results from questionnaire.............................................................................28

4.3 Testing the reliability of scales and observed variables in the model.............29

4.3.1 Testing scales for factor “work”............................................................30

4.3.2 Testing scales for factor “promotion opportunities”.............................30

4.3.3 Testing the scales for factor “salary”.....................................................31

4.3.4 Testing scales for factor “supervisors”..................................................31

4.3.5 Testing scales for factor “co-workers”..................................................32

4.3.6 Testing scales for the dependent variable “job satisfaction”.................32

4.4 Explore factor analysis....................................................................................33

iv

4.4.1 Explore factor analysis with independent variables..............................33

4.4.2 Explore factor analysis with the dependent variable “job satisfaction” 36

4.5 Building regression function and testing research hypotheses.......................37

4.5.1 Estimating regression function from data set........................................37

4.5.2 Testing research hypotheses..................................................................38

4.6 Testing the differences between different groups of employees by

demographic variables.............................................................................................39

4.6.1 Testing differences between variables by gender..................................39

4.6.2 Testing differences between variables by age.......................................42

4.6.3 Testing differences between groups by education level........................45

4.6.4 Testing differences between groups by work experience......................46

4.7 Discussion.......................................................................................................47

Chapter 5 Conclusions and Recommendations...............................................................50

5.1 Conclusions.....................................................................................................50

5.2 Recommendations from research results........................................................50

5.3 The importance of the study...........................................................................51

5.4 Limitations of the study..................................................................................51

5.5 Directions for future researches......................................................................51

References.......................................................................................................................53

Appendix.........................................................................................................................55

v

List of Tables

Table 1. Results of business targets in 2012......................................................................3

Table 2. The results from questionnaires........................................................................28

Table 3. Results from testing scales for factor “work”...................................................30

Table 4. Results from testing the scales for factor “promotion opportunities”...............31

Table 5. Results from testing scales for factor “salary”..................................................31

Table 6. Results from testing scales for factor “supervisors”.........................................32

Table 7. Results from testing scales for factor “co-workers”..........................................32

Table 8. Results from testing scales for the dependent variable “job satisfaction”........33

Table 9. KMO and Bartlett's Test with independent variables........................................34

Table 10. Total variance extracted of independent variables..........................................34

Table 11. Rotated Component Matrix of independent variables.....................................35

Table 12. KMO and Bartlett's Test with the dependent variable....................................36

Table 13. Total Variance Explained with the dependent variable...................................36

Table 14. Component Matrixa.........................................................................................36

Table 15. Model Summaryb.............................................................................................37

Table 16. ANOVAa..........................................................................................................37

Table 17. Coefficientsa....................................................................................................37

Table 18. Statistics by gender group...............................................................................40

Table 19. Independent Samples Test..............................................................................40

Table 20. Variance analysis by age................................................................................42

Table 21. Result from analysis of multi groups by Tukey value.....................................44

Table 22. Variance analysis by education level..............................................................45

Table 23. Variance analysis by work year.......................................................................46

vi

List of Figures

Figure 1. Research Structure.............................................................................................5

Figure 2. Maslow’s Model................................................................................................8

Figure 3. The Porter and Lawler Model..........................................................................11

Figure 4. The research model..........................................................................................20

Figure 5. Sample structure by Gender.............................................................................26

Figure 6. Sample structure by Age..................................................................................27

Figure 7. Sample structure by Education Level..............................................................27

Figure 8. Sample structure by year experience...............................................................28

vii

viii

Chapter 1 Introduction

This chapter will introduce the research background, research motivations,

research purposes and research procedures. The contents in detail are as follows:

1.1 Research Background

The trend of regionalization and globalization put more stress on competition

among businesses. To sustain and develop in a market, all business are required to

obtain a unique strengthen to have advantage over other businesses in any competition

and affirm its position. Changes in business sector have to accept that the only

advantage as well the most sustainable advantage is human.

Any changes in business sector increase more stress, pressure on companies,

requiring them to change, take initiative in creation, utilizing advanced techniques,

creating new products and new services to meet the increasing need of customers.

Meanwhile, it also requires that Company to attract more qualified employee, maintain

and improve their human resources.

One of the leading criterions for assessing quality of investment environment is

labor resources. It is impossible for a business to make a breakthrough step if their

employees are unqualified or dishonest. The organization of their employees must be

proficient to maximize their strength.

According to human resources experts, assessment job satisfaction of a staff is a

key task for a business to develop human resource sustainably. Of course, this task must

be implemented upon some criterions for different position and must be carried out

periodically in-person discussion basis. There is no good if an employee is recruited

without a job description. Because without a job description, the candidates cannot

imagine his/her tasks to express him/her during the interview and then when he/she is

recruited, it is very hard for this person to work. In many cases, they are afraid of being

unfair treated. The bonus – punish regime must be fair and transparency, so does the

employee appraisal. Besides that, in appointing a position, the leader must consider the

characteristics of an employee to make the most suitable coordination between different

people with different characteristic to make a good team (of which everybody can fulfill

the other).

In the context of present direct competition, there are various reasons for a staff to

quit his/her job, such as feeling unsatisfied with material interests, no respect, no

sharing from supervisors, no motivation, no promotion, no training, unclear policy,

strict supervise, no coordination from colleagues, unfairness, bad working environment,

no democracy, etc. If the human resource is not planned efficiently, the business will

face damaged troubles if anything wrong happen.

In Vietnam, the study of satisfaction of employees (if any) shall only be

conducted internally by the HR department is responsible. This is still pretty much

limited as much experience not to influence errors, expensive cost and time investment,

no concrete results with the goal of what to do, not the Human Resources department

creates enough influence to convince operating successful.

Black & Porter (2000) showed that all activities within an organization can be

traced to human involvement and capabilities. The factors determining job satisfaction

has been extensively researched in many developed countries in the world (Cranny et al.

1992).

Similarly, Ting (1997) states that empirical evidence consistently indicates that

job characteristics such as pay satisfaction, opportunities for promotion, task clarity and

relationships with co-workers and supervisors have significant effects on job

satisfaction of employees. In support, a study conducted by Ellickson and Logsdon

(2002) reflected that job satisfaction of employees was significantly influenced by

perceptions of employee satisfaction in terms of pay, promotional opportunities,

relationships with supervisors, employees performance management systems and fringe

benefits.

Some information about Hai Duong Power Company (HDPC)

Company’s name: Hai Duong MTV Power Co., Ltd - North Power Corporation.

Date of establishment: 08-4-1969.

Headquarter: No. 33 Ho Chi Minh Avenue - Hai Duong City - Hai Duong

Province

Pursuant to the Charter of organization and operation of Hai Duong MTV Power

Co., Ltd, which is approved by Chairman of the company, the production model of Hai

Duong Power Company is arranged as follows:

Hai Duong MTV Power Co., Ltd has 1.300 staffs with following classification of

education level:

Male employees: 839 persons (74,45 %); female employees: 288 persons

(25,55%).

Employees above university-level: 20 persons (1,54 %)

Employees at university-level: 601 persons (46,23 %)

Employees at college-level: 147 persons (11,31 %)

Employees at intermediate-level, and workers: 532 persons (40,92%)

Company leaders including President as well as Director; 01 Comptroller; 04

Deputy Directors; 01 Union president and Vice Secretary of the Party Committee

Advisory unit: include 13 division departments

Production unit: 12 powers; 1 factory;

Auxiliary Unit: 01 Power testing factory; 01 facility repairing factory, 01 power

installation factor, 01 design consultancy factory, and 01 Project Management

department.

Table 1. Results of business targets in 2012

No Targets Unit Assigned tasks PerformanceComparing

ratio

1 The loss of electricity kWh 3.184.738.738

2 Commercial power kWh 2.683.000.000 2.687.259.908 1,00

3The electricity loss percentage

% 6.30 6.14 -0,16

4Average electricity price

VND/kwh 1240,10 1.244,71 4,61

5 Total revenue millions 3.327.188,30 3.352.220,56 1,01

6Total number of clients

contract 481.263

1.2 Research Motivations.

In this thesis, the main motives that promote author to research are:

Hai Duong Power Company is facing up with the challenges and difficulties,

most of which is human resource management.

There is in the company lack of qualified and skilled staffs; working condition

with high risks, and the pay and appraisal systems is not good and does not motivate

employees.

Many staffs feel dissatisfied when they have to travel far to work.

No research on the job satisfaction of the staff at Hai Duong Power Company

before.

In addition, Development of a research program on employees’ satisfaction in

power companies in Vietnam in this period is very important. After many years of

working, the managers as well the employees tried to run and develop a Company.

However, recently, while the managers tried to promote the business, they faced

troubles with human resources. During the last 3 years, number of staff who left the

Company is high. There are many reasons for this problem and this fact affect badly on

Company’s income and image.

1.3 Research Purposes

To find out what factors affect job satisfaction among HDPC employees and to

investigate job satisfaction in HDPC.

Assessment the difference in Job satisfaction between staffs to identify

dimensions that influence to Job satisfaction, such as: Gender, Work position,

Education level, working experience years.

To propose solutions to acquire higher job satisfaction in Hai Duong Power

Company.

1.4 Research Procedure

The procedures of this study are shown in figure 1

Figure 1. Research Structure

Step 1: Defining research objectives: At this step, the author identifies research

issues and objectives of the study, in details here is evaluating the satisfaction with job

of employees at Hai Duong Power Company. The purpose is to evaluate factors

affecting job satisfaction of employees and how demographic factors influence job

satisfaction; as well as the impact intensity of each factor on general satisfaction level.

Step 2: Writing chapter 1: At this step, the author does based on instructions from

STU on necessary contents for the part of introduction including: research background,

research motivations, research methodology, and research procedure.

Step 3: Writing chapter 2: This is the step at which the author collects results

from previous studies on job satisfaction, about definitions, theories of job satisfaction,

factors affecting job satisfaction, and the effect of job satisfaction with research units.

Step 4: Writing chapter 3: Based on theoretical basics, model and results from

other researches, the author will build an appropriate research model to select as an

official theoretical model for the study. In detail in this study, the author selects JDI

model and other necessary methods to achieve posed research purposes.

Step 5: Designing questionnaire: Questionnaire will be designed and trial done to

get comment and opinions from research objects. After that, they will be adjusted to get

the final official research for actual survey.

Step 6: Collecting data: After completing questionnaire for actual survey,

questionnaire will be distributed to employees to get actual data for analysis. Obtained

data will be cleaned and analyzed.

Step 7: Analyzing data: Data after cleaned will be analyzed with the support of

SPSS software by such as: testing the reliability of scales, explore factor analysis,

regression analysis, and variance analysis to get answers for questions posed in the part

of research purposes.

Step 8: Conclusions and recommendations: This is the last step of the study.

Based on the results from data set, the author will summarize main results and propose

solutions as well as directions for further researches. At the same time, the author also

generally rechecks all parts and completes the thesis.

Chapter 2 Literature Review

This chapter will present contents of theories on job satisfaction, advantages of

creating job satisfaction, factors affecting job satisfaction, and effects of job satisfaction

on employees. The contents in detail are as follows:

2.1 Definition of job satisfaction

Job satisfaction is not a unified concept because it comes from different

perspectives of other researchers. Kusku (2003) supposes that job satisfaction reflects

needs, desires and perceived feelings of employees about their job. This definition

comes from the theory of Maslow's hierarchy of needs (1943) which supposes that

employees feel satisfied if their needs are met from low to high level. Wright and Kim

(2004) also suppose that job satisfaction is the appropriateness between what employees

want from job and what they feel about job. Some other researchers consider job

satisfaction as positive feeling state of employees with job and it is expressed through

their behavior and belief (Vroom, 1964; Locke, 1976; Quinn and Staines, 1979; Weiss

et al, 1967).

Some researchers suppose that job satisfaction is the satisfaction with aspects of

job. The level of satisfaction with each aspect of job will affect attitudes and awareness

of employees. This is clearly proven in the research on Job Descriptive Index (JDI) of

Smith et al (1969 quoted from Luddy, 2005). In the research of Smith et al, job

satisfaction is expressed in five main factors including: (1) work, (2) promotion

opportunities, (3) supervisors, (4) co-workers, and (5) salary. These aspects of job from

Smith’s study are also recognized by many researchers in different researches (Spector,

1997; Tran Kim Dung, 2005; Luddy, 2005).

In general, there are two ways to define job satisfaction including (1) considering

job satisfaction as a general variable that brings emotional nature (positive and negative)

of employees with job affecting their belief and attitudes; (2) considering job in

different separate aspects of job. In this study, job satisfaction is mentioned both in

aspects of job and general satisfaction of employees.

2.2 Theories of job satisfaction

2.2.1 Maslow's hierarchy of needs

According to Maslow, there are numerous levels of human satisfaction in

order from bottom to top. Accordingly, people all have five types of need as

follows (figure):

Figure 2. Maslow’s Model

In which:

Level 1: Basic needs or biological needs including needs to ensure human

existence such as eating, drinking, wearing, surviving, developing race and other

needs of the body.

Level 2: Needs for security and safety: needs for protection from elements,

security, order, law, limits, stability, etc.

Level 3: Social needs or needs for linking and acceptance: needs for love,

for friends, for being accepted, etc.

Level 4: Esteem needs: needs for self-respect, for others respect, for having

a status, etc.

Level 5: Needs for self-actualization or self-mobilization: needs for truth,

goodness, beauty, self-reliance, creativity, humor, etc.

These five levels of need are divided into two groups including low need

level (level 1 and 2), and high need level (level 3, 4, and 5). The differences

between these two groups are that: The low needs are endogenous needs

(physiological, safety needs, etc.) which are born from the inside demand of

people; and high needs or exogenous needs (communication, respect and self-

improvement needs, etc.) which are social need arising from external demands.

Maslow’s hierarchy of needs is widely recognized and applied in practice during

the 1960s and 1970s (Robins et al, 2002). The weakness of the theory of Maslow

is not to provide empirical evidences for the theory and some researches to

confirm its value also failed (Robins et al, 2002)

2.2.2 McClelland's achievement motivation theory

David Mc. Clelland (cited by Robbins et al, 2008) suggests that humans

have three basic needs: need for achievement, need for affiliation, and need for

power. In which:

(1) The need for achievement

People with high need for achievement are always trying to realize their

works better. They want to overcome difficulties and obstacles. They consider

that their successes or failures result from their actions. It means that they prefer

challenging tasks. This is the kind of people who work better when they are

motivated. Common characteristics of people with high need of achievement are:

- Desire to carry out personal responsibilities

- Tendency to set high goals for themselves

- High demand for specific and immediate responses

Mastering quickly and early their work

(2) The need for the affiliation

Similar to Maslow social needs, it is the need to be accepted such as needs

for love, need for friends. Employees have strong need for affiliation will work

well in the friendly and social working environment.

(3) The need for power

This is the need to control and influence others in their work environment.

Researchers point out that people with strong needs for power and for

achievement tend to become managers. Some also assume that successful

executives have the strongest need for powerful, followed by the need for

achievement and finally the need for affiliation.

2.2.3 Vroom’s Expectancy theory

Vroom (1964) suggests people are motivated at work to reach goals if they

believe in valence of those goals, and they can see the work they do can help them

to reach the goals. Vroom’s theory asserts that motivation at work is defined by

valence they put in their efforts’ outcome and multiplied by the belief they have.

In other words, Vroom’s theory indicates motivation is the product of expected

valence that people put in goals and opportunities they see to accomplish the

goals:

Motivational Force (MF) = Expectancy x Instrumentality x Valence.

When a person is indifferent of achieving goals, then his/ her passion is

considered equal to zero; and the passion will be below zero when that person

rejects reaching the goal; the results of the two situations are not motivation

created. Similarly, a person may have no motivation to reach the goal if

expectancy is zero or negative:

2.2.4 Motivation theory

E. Lawler (1974 cited from Robins et al 2002) developed a more complete

version of motivation depending upon expectancy theory built a more perfect

motivation model and mostly base on Expectancy theory (Figure 3).

As the model mentioned, all effort or strength of motivation depend on the

value of the reward and the probability or possibility of getting that reward. Next,

task performance is determined by motivation, ability to work of people

(knowledge and skills) and the perception of the tasks required. So performance is

the responsible factor that leads to intrinsic as well as extrinsic rewards. These

rewards, along with the equity of individual lead to satisfaction. Hence,

satisfaction of the individual depends upon the fairness of the reward.

Figure 3. The Porter and Lawler Model

This model is more appropriate to describe the system of motivation. The model

shows that motivation is not a simple cause and effect problem.

2.3 Advantages of employee satisfaction

Human resource is the decisive factor in the development of the organization

(Wheeland, 2002). To create loyalty and attachment to the organization, it is needed to

create employee satisfaction with the job they are doing. Creating job satisfaction and

loyalty helps organizations reduce the cost of recruitment, training and reduce errors in

the process of working down from the new employee. The staffs who are highly skilled

and experienced usually complete work in a short time compared to the new staffs

lacking of work experience.

The experts on quality in U.S. such as Deming or Juran said that job satisfaction

will lead to productivity and performance of the company. The expert on quality in

Japan as Ishikawa (1985) always stressed the importance of the "human element" to

create an environment of high quality work. Ishikawa supposed that effective quality

control should be based on people management. The research of Saari and Judge (2004)

Perceived effort reward probability

Perceived Equitable reward

Perception of task required

Ability to do specific task

Value of rewards

Extrinsic rewards

Intrinsic reward

Performance Accomplishment

Satisfaction

Effort

also showed that job satisfaction affects job performance of employees. In general,

research shows that job satisfaction will make employees more loyal, or strike down

state or increased union activity (Saari and Judge, 2004).

2.4 Factors affecting job satisfaction

Factors that affect job satisfaction of employees are described by JDI. These

factors include: work, promotion opportunities, supervisors, co-worker, and salary:

2.4.1 Work itself

The job satisfaction depends on the satisfaction with the work components,

such as the nature of job (Loke, 1995 cited from Luddy, 2005). The relevance of

the work to workers is expressed through many aspects of the nature of work: use

of different skills, employees' understanding the work process, and certain

importance of the work for the organization. In addition, the work must be in

accordance with workers' capacity. Many different studies tested relationship

between “work itself” and job satisfaction of employees (Luddy, 2005; Ha Nam

Khanh Giao, 2011; Chau Van Toan, 2009).

2.4.2 Promotion opportunities

Some researchers supposed that promotion opportunities closely link with

the job satisfaction of employees (Pergamit & Veum in 1999; Peterson et al, 2003;

Sclafane, 1999 cited from Luddy, 2005). This view is supported by research by

Ellickson and Logsdon (2002) which shows that advancement opportunities are

believed to have a positive influence job satisfaction. However Kreitner and

Kinicki (2001) supposed that positive relationships between development

opportunities and job satisfaction depend on fairness perceptions of employees. In

Vietnam, the studies of Tran Kim Dung (2005), Chau Van Toan (2009) with staffs

working in the office in Ho Chi Minh City also show that promotion opportunities

have positive impact on job satisfaction. The study of Ha Nam Khanh Giao (2011)

with employees working in the field of manufacture of beverages (Tan Hiep Phat

Corporation) also shows that the factor “promotion opportunities” has influence

on job satisfaction of employees.

In some studies in Vietnam (such as Tran Kim Dung, 2005; Ha Nam Khanh

Giao, 2011), the factor “promotion opportunities” is considered in aspects such as:

Fully professional trained, opportunities to improve the professional skills, create

opportunities for those who can afford, chance for individual developments, and

training and promotion policies are clear.

2.4.3 Supervisors

“Supervisor” is understood as the direct manager of employees. Supervisor

makes employees satisfied through their communication, their attention and care

for their subordinates, or their act of protecting employees when it is necessary,

and through demonstrating their leadership ability and professional capacity in

front of their staff (Robins et al, 2002).

In addition, employees feel satisfied with their supervisor thanks to their fair

treatment, or sincere recognition of employees' contribution. According to

Ramsey (1997, cited from Luddy, 2005), leadership affects working morale high

or low. Attitudes and behaviors of leaders for employees could also be factors

affecting the behavior or uncooperative co-workers. The leadership style

democracy creates more sympathy from employees. It can promote learning and

reduce the frustration in work when employees are motivated on time. Many

actual researches also show positive relationship between the factor “supervisors”

and job satisfaction (Koustelios, 2001; Peterson, Puia & Suess, 2003 cited from

Luddy, 2005; Tran Kim Dung, 2005; Ha Nam Khanh Giao, 2011).

2.4.4 Co-workers

C-workers are people working together in the organization or the people

working in the same department. Friendly co-worker relation will increase the

satisfaction with job of employees (Johns, 1996; Kreitner & Kinicki in 2001 cited

from Luddy, 2005). The factor “co-workers” is considered good is in the

organization, employees are always willing to help each other, work together

effectively, treat well, working environment is friendly, and employees have

reliable relations. The relationship between factor “co-workers” and “job

satisfaction” is tested in many different studies. The study of Madison (2000 cited

from Luddy, 2005) with 21.000 women showed that for works that require

rigorous without the support of colleagues, the ability of dissatisfaction with job

of employees will be higher. Many actual researches also showed positive

relationship between co-worker’s supports and the job satisfaction (Luddy, 2005;

Chau Van Toan, 2009; Ha Nam Khanh Giao, 2011; Pham Van Manh, 2012).

2.4.5 Salary / Pay

The salary is the amount the employee earned while completing the job.

Some studies suggest that there is little empirical evidence that wages affect job

satisfaction. Workers may have high-income but they still do not feel satisfied

with job if it does not fit their capacity and skills or they do not fit in with work

(Bassett, 1994 cited from Luddy, 2005). However, the study of Oshagbemi (2000)

showed the relationship between salary and job satisfaction by statistical analysis.

The factor “salary” in this study is considered in some aspects such as: the

mismatch between salary and employee's contribution, employees can live on

their salary, or the reward and allowances policies are fair. In addition, the author

also compares salary of employees at the company with other units. We can see

that in the conditions of Vietnam, salary or income is still an important factor

affecting job satisfaction (Tran Kim Dung, 2005; Pham Van Manh, 2012).

JDI becomes more popularly to evaluate the satisfaction level with job. In

this study, the author tests the effects of factors in JDI model on general job

satisfaction. Details here are five main factors including (1) work itself, (2)

promotion opportunities, (3) supervisor, (4) co-worker, and (5) pay and measure

how they have impact on the satisfaction with job of employees in Hai Duong

Power Company.

2.5 The effects of job satisfaction

Luddy (2005) summarized some effects of job satisfaction on productivity, the

leave and absence of work:

2.5.1 Overall Performance

The research results show that the relationship between job satisfaction and

performance is positive, but small and inappropriate (Johns, 1996).

According to Luthans (1989), although some relations between satisfying

employees with job and their productivity exist, but the relationship between these

variables is not strong. Authors suppose that employees who feel much satisfied

with job may be not effectively working staffs.

At the private companies, there may be no significant relationship between

job satisfaction and performance, but in some organizations, a close relationship

exists between job satisfaction and performance (Robbins et al 2003).

2.5.2 Quitting the job

Some studies agree with the viewpoint supposing that “job quit” has

negative impact with job satisfaction (Griffon, Meglino & Mobley (1979) and

Price (1977) cited in Robbins et al, 2003).

According to French (2003), the ratio of job quit of employees often

happens in an environment where the employees feel dissatisfied. Greenberg and

Baron (1995) supposed that employees have tendency to quit their job as a way to

express their dissatisfaction. By not reporting or resigning to seek a new job

prospects, employees can express their dissatisfaction or try to escape the

unpleasant aspects that they can meet. Phillips and Phillips (2001) agree that job

quit of employees is the most important factor.

The study of Steel and Ovalle (1984) established a very close relationship

between job satisfaction and job quit. It showed that employees with

dissatisfaction with job may tend to leave their job. According to Lee and

Mowday (1987) cited in Luthans (1989), there is a relationship existing between

job satisfaction and job quit.

The researchers also admitted that making employees feel satisfaction with

job does not mean to reduce trend of job quit from employees, but it supports in

maintaining a low rate of quitting.

2.5.3 Absence of work

The study shows that the level of job satisfaction has impact on the absence

of work (Hellriegel, Slocum & Woodman, 1989).

Nel et al. (2004) said that "absence “ is considered as a withdrawn behavior

when it is used as a way to get rid of a working environment that is not desirable".

According to Luthans (1989), many studies are done based on a negative

relationship between job satisfaction and job absence. Hence, if the satisfaction is

low, absence tends to become higher. Contrary to this, the study of John (1996)

showed a moderate relationship between job satisfaction and job absence.

Robbins (1993) agreed with above conclusion of John (1996). According to

Robbins et al. (2003), the moderate relationship between these variables may

come from the fact that employees can be free absent if they feel sick. This reason

may reduce the correlation coefficient between job satisfaction and absence.

Chapter 3 Research Methodology

This chapter will present research methods used to investigate relations between

employees of the company and their managers at Hai Duong Power Company on job

satisfaction. Selection of samples, measurement tools, methods of data collection and

other statistical techniques are also mentioned in this chapter.

3.1 The population and research sample

The purpose of this study is to evaluate the job satisfaction level of employees at

Hai Duong Power Company. So, the research objects of the study include all employees

working at the company. The selection of the study plays an important role in defining

the overall of study because it will help the author establish sample size and objects,

which are highly representative for the population (Nguyen Cao Van, 2009).

To ensure the reliability of the study, selecting an appropriate sample size is

necessary. General principle for selection of sample size is that the bigger sample size

is, the higher accuracy of research results will be. However, if the sample size is too big,

it will affect time and cost to do the research. Therefore, researchers often recommend

selecting a sample size that is appropriate with the ability of study and ensures

necessary reliability (for example: Suanders et al, 2007; Nguyen Dinh Tho, 2011). The

principle for defining necessary sample size depends on the overall of study as well as

analysis methods. Methods of sample selection often bases on the principle of sampling

principle in two times. At the first time, taking random samples of 100 to 200, and next

according to the standard deviation and statistical inferences to determine the

appropriate sample size (Nguyen Cao Van, 2009). Some other researchers make

experience rules for sampling by methods of explore factor analysis or regression

analysis method. For example Lee and Comrey (1992 quoted from Maccalum et al,

1999) gave the sample size for the respective views as follows: 100 = bad, 200 = pretty,

300 = good, 500 = very good, 1000 or more = excellent. In general, rules of experience

sampling have inconsistencies between different researchers. In the scope of this study,

because of limitation on research resources, the sample size will base on minimum

principle to ensure the necessary reliability. Thus, the sample size is defined = 200

according to the principle of Lee and Comrey (1992). It is a good sample size and

satisfies many other sampling principles.

After defining sample size, questionnaires will be completed and distributed to

employees working at Hai Duong Power Company. The time for collecting data will

last from February to April, 2013.

Data collection method: To collect research data, after building final questionnaire

(see more in 3.4), the author will start distributing questionnaire to employees working

in Hai Duong Power Company. Questionnaires will be sent to managers of departments

along with answering instruction to ensure that employees understand right about the

content of questions. After employees fill in information in answer sheets,

questionnaires will be collected by leaders and sent to the author to summarize and

analyze research results.

3.2 Measurements

JDI model is used in this study to design questionnaire and to collect actual data.

3.2.1 The reliability of JDI

Anastasi (1990, quoted from Luddy, 2005) supposed that the reliability is

the consistency of the evaluation values obtained by the same person when

examining in different tests. In other words, the reliability of scales for factor or

for a research model is evaluated based on its other repeated researches which also

ensure the reliability. To test the reliability of each research definition, we use

many different methods such as: Split – half technique; item analysis and popular

is using Cronbach Alpha coefficient.

Researches using JDI show that definitions in JDI are reliable definitions.

According to Smuker et al (2003 quoted from Luddy, 2005) there are 78 survey

with female sports reporter by using JDI model and they all show that factors in

JDI model ensure their high reliability with Cronbach Alpha coefficient greater

than 0.7. Other researches in the United States provide evidences of the reliability

of factor in this model. For example, the study of Futrell (1979) Alpha

coefficients of factors are from 0.67 to 0.96, in the study of Nagy (2002), Alpha

coefficient are from 0.83 to 0.9 (quoted from Luddy, 2005). In Vietnam, recent

researches of Tran Thi Kim Dung (2005), Chau Van Toan (2009) or Pham Van

Manh (2012) also proved that using definitions in JDI model is appropriate

because they ensure the reliability with Cronbach Alpha coefficients greater than

0.6. In conclusion, we can see that JDI is a reliable index to be used for researches

on job satisfaction.

3.2.2 The validity of JDI

JDI becomes more popular in many researches on measuring job

satisfaction level of many other researchers. Nagy (2002 quoted from Luddy,

2005) supposed that there are 400 studies and documents proving the validity of

JDI. Different researches point out the relations between factors of Job in JDI and

job satisfaction. For example, the study of Luddy (2005), study of Chau Van Toan

(2009) proved that factors in JDI reach distinction value. This is also tested in the

study of Kincki et al (2002) which shows that JDI achieve consistency, reliability,

and convergence value and distinction value. Through that the validity of JDI is

confirmed.

3.2.3 Reasons for selecting JDI

Using JDI becomes more and more popular in measuring job satisfaction in

many researches. According to Kerr (1997 quoted from Ha Nam Khanh Giao,

2011), JDI has basic and reliable research definitions. Luddy summarizes some

comments of other researches about the reason why they selected JDI to measure

job satisfaction as follows:

Smith (1969) quoted from Spector (1997) supposes that JDI is a valuable

and reliable method which is used to measure job satisfaction;

Vorster (1992) quoted from Cockcroft (2001) concluded that JDI has been

standardized and found to be consistent with the conditions in the different

studies;

JDI is considered as a careful design and the most popular tool to measure

job satisfaction (Vroom, 1964 quoted from Schneider & Vaught, 1993). There are

more than 50% world's leading articles published on management from year 1970

to 1978 related mention the use of JDI on survey on job satisfaction (Yeager,

1981 quoted from Schneider & Vaught, 1993);

JDI was already used in before surveys in the region to measure job

satisfaction level of employees (Schneider & Vaught, 1993).

JDI is easy to use and does not require reading ability to complete

(Heneman, Schwab, Fossum and Dyer, 1983).

3.3 Research model and hypotheses

In the scope of this study, JDI associated with the factor “general job satisfaction”

is referenced from Spector (1995) and from other studies in Vietnam using JDI model in

measuring job satisfaction (for example: Tran Kim Dung, 2005; Chau Van Toan, 2009;

Ha Nam Khanh Giao, 2011; Pham Van Manh, 2012). Different with other researches

(for example the study of Luddy (2005) using 72 questions from JDI model of Smith et al

(1969 cited from Luddy, 2005), this study established many adjusted questions with

different levels than yes – no questions and still used five original factors in JDI model.

The research model will include 5 factors from JDI as follows:

Figure 4. The research model

Then the research hypotheses are:

The factor “work itself” reflects the appropriate level of the job with the capacity,

and desire of workers. An appropriate job is expressed in some aspects such as: the

appropriateness with capacity, professional skill, ability to clearly understand job,

opportunity to use personal capacities of employees and comfortable feeling to realize

job assignments (Luddy, 2005). Various studies have proven the link between the "work

itself" factor and job satisfaction of employees. The relationship between them is a

positive relation (Luddy, 2005; Chau Van Toan, 2009; Ha Nam Khanh Giao, 2011).

Therefore, in this study, the first hypothesis is:

H1: The factor “work itself” positively affects job satisfaction.

Promotion opportunities: This factor expresses staff’s awareness about their

opportunities to be trained, to develop personal capacity and to advance within the

organization. Training and promotion opportunities can be seen as motivation factors in

Herzberg's two-factor theory, improving these factors will increase the job satisfaction

level of employees. Employees will feel satisfied with the job, which gives them

opportunities to be trained on personal skills and to advance in their career. This is

proven through studies of many researchers (Tran Kim Dung, 2005; Ha Nam Khanh

Giao, 2011; Pham Văn Manh, 2012). Hence, the second hypothesis of this study is:

H2: The factor “promotion opportunities” positively affects job satisfaction.

"Salary" reflects employee perception on the fairness (inside and outside) in

salary. Salary is the remuneration that the employees earn for their work in the

organization. According to Maslow's theory of needs, the need for pay is equivalent to

the basic needs, physiological needs. It is endogenous and must be satisfied. In general,

at the same level of work the employees will feel more satisfied when their income is

higher. In a developing country like Vietnam, “salary” is still an important factor

affecting the satisfaction with job (Tran Kim Dung, 2005; Pham Van Manh, 2012). So

this gives out following hypothesis:

H3: The factor “salary” positively affects job satisfaction.

"Supervisors" is related to the relationship between employees and their direct

supervisors, the support of their superiors, leadership style and leadership abilities to

perform administrative functions of managers within the organization. Supervisor is a

direct manager who manages activities of employees (Robins et al, 2002). Supervisor's

caring for employees is a good way to motivate them, to reduce their dissatisfaction at

work. In other works, "Supervisors" factor has a positive impact on employee

satisfaction at work. This has been proven through studies of numerous researchers

(Luddy, 2005; Tran Kim Dung, 2005; Ha Nam Khanh Giao, 2011). Therefore, this

study proposes hypotheses as follows:

H4: The factor “supervisors” positively affects job satisfaction.

"Co-workers": indicates colleague behaviors, co-worker relations in the

workplace. Co-workers are people who work together at the same place with similar

work content. Relationships between co-workers are competitive and supportive.

Employees will feel satisfied with their job if they get good support from their co-

workers; their co-workers are friendly and help each other at work as well as rewards

and promotion policies in the organization are fair. In other words, employees will feel

more satisfied at work when they have good relationships with their co-workers. Many

researches showed the positive relationship between the factor “co-workers” with job

satisfaction (Luddy, 2005; Chau Van Toan, 2009; Ha Nam Khanh Giao, 2011; Pham

Van Manh, 2012). Thus, this study hypothesizes that:

H5: The factor “co-workers” positively affects job satisfaction

3.4 Scales for research variables and design of questionnaire

This study uses the basic theoretical JDI which is developed by Smith et al (1969)

with five main factors including independent variables and the dependent variable “job

satisfaction”. The value and reliability of JDI model are proven, however initial

researches still use Yes – No questions. According to Nguyen Dinh Tho (2011),

nowadays with the development of scale building, scales with many assessment levels

will be more appropriate and reliable than others. In many scales (Stapel, Likert),

Likert is the most popular scale in sociological studies. In recent studies (for example:

Tran Kim Dung, 2005; Chau Van Toan, 2009, Pham Van Manh, 2012, etc), the authors

also used Likert scale to measure factors in the research model which use JDI model

instead of Yes- No questions. Therefore, in this study, the author also use five-point

Likert scale to measure observed variables.

Observed variables are built based on basic theoretical JDI model, and at the same

time the author also references some other researches in Vietnam such as the study of

Tran Kim Dung (2005), study of Chau Van Toan (2009), Pham Van Mạnh (2012). And

these observed variable are also adjusted to suit Vietnamese research conditions through

trial interviews with employees to test if they understand right the contents of questions

in the questionnaire or not. In detail, factors are measured through observed items as

follows:

For the factor “work”: This factor is measured by six different observed items

referenced from the theory of Smith et al (1969), research of Tran Kim Dung (2005),

Chau Van Toan (2009) and adjusted to suit new research condition. In detail, observed

items for factor “work” are:

(1) The work suits the capacity and professional knowledge.

(2) Clear understanding of the work

(3) The work allows chance for development of individual ability.

(4) There is motivation for creative work

(5) The work is interesting and challenging

(6) Work assignments are reasonable.

For the factor “promotion opportunities”, an important factor for employee:

Promotion often brings much more income as well as recognition of capability. In this

study, the factor “promotion opportunities” is built by five observed items based on

inherits from JDI model. Questions are referenced from studies of Tran Kim Dung

(2005), Chau Van Toan (2009) for office employees in Vietnam. The contents of

questions are as follows:

(1) Fully professional trained

(2) Opportunities to improve the professional skills

(3) Create opportunities for those who can afford

(4) Chance for individual developments

(5) Training and promotion policies are clear.

For the factor “salary”: This factor is measured by five different observed items

which are inherited from the studies of Tran Kim Dung (2005), Pham Van Manh (2012)

and adjusted to suit the research unit’s conditions. They include:

(1) Salary is in accordance with the capabilities and contributions.

(2) Fair rewards for effective work

(3) Equitable distribution of salaries, bonuses and allowances for the

contributions.

(4) Can live on current income

(5) Salary is equal to other units

For the factor “supervisors”: This is measured by four observed items. These

items are referenced from JDI model of Smith et al (1969) and Tran Kim Dung (2005)

as well as from studies of Tran Van Manh (2012), and Chau Van Toan (2009). They are

also adjusted through trial interviews with employees. The contents of observed items

are as follows:

(1) Supervisors take care of subordinates

(2) Employees obtain supports from supervisors

(3) Supervisors fairly treated every employees

(4) Supervisors has good performance, vision as well as leadership skill

For the factor “co-workers”: In this study, the factor “co-workers” is measured by

observed questions based on studies of Tran Kim Dung (2005) and Chau Van Toan

(2009). At the same time, observed items are also adjusted to suit new research

conditions but still have initial meaning. For this factor, there are following four

observed items:

(1) Co-workers are ready to help each other

(2) Co-workers coordinate to work well

(3) Co-workers are very friendly

(4) co-workers are very trustworthy

A weakness of JDI model is that there are no scales for general satisfaction level

(Spector, 1997 quoted from Vo Thi Thien Hai and Pham Duc Ky, 2010). Therefore,

using traditional JDI just evaluate the satisfaction with aspects of job not general

satisfaction level. To overcome this, Spector propose to measure general satisfaction by

three observed items including (1) In general, I feel satisfied with your job, (2) In

general, I like my job, and (3) In general, I like to work here. Studies in Vietnam (for

example: studies of Tran Kim Dung, 2005) consider the satisfaction with job as is

comfortable, stick with the job and respect the work. In the scope of this study which is

referenced by study of Tran Kim Dung (2005), there are some adjusts and add of three

new observed items to measure the factor “general satisfaction” including:

(1) Feel satisfied working here

(2) Feel happy when be chosen to work here

(3) Consider the company as the second home

After developing scales for each factor in the research model, the author continues

building questionnaire for actual survey. In principle, questionnaire needs to be built

simply and conveniently for answers of employees as well as analysis of data set later.

Based on the consultation of colleagues and employees, the questionnaire is designed

including three following parts:

(1) Personal information of asked people

(2) Contents of main questions (observed variables in the model)

(3) Open comments of employees

(See Appendix 01)

3.5 Data analysis

Collected data is analyzed by using statistical analysis techniques such as:

descriptive statistics, testing scale reliability, exploratory factor analysis, correlation

analysis, multiple regression analysis, testing hypothesis by statistics. The cycle of

research analysis is described as follows. Including:

3.5.1. Descriptive statistics

Obtained samples will be statistically classified based on the criteria for

classification such as: gender, age, education level, work position and income. At

the same time, the author also calculates the Mean value (average value),

maximum value, minimum value and standard deviation of answers from data set.

3.5.2. Scale verification

Factors are tested by Cronbach`s Alpha coefficient and the total correlation

coefficient (Item-total correlation). Observed items not ensuring the reliability

will be removed from the scale and not appear in the step of factor analysis. In

this study, Cronbach`s Alpha must be at least 0.6 (Hair et al, 1998). The Item-total

correlation which is greater than 0.3 will be considered as a spam item and then

removed from scale (Nunally and Burstein, 1994)

3.5.3. Explore factor analysis

Definitions (factors) after by Cronbach`s Alpha tested will be processed by

Explore factor analysis (EFA). Explore Factor Analysis will help the author

reduce the observed variables into fewer latent variables and they will be more

meaningful in explaining the research model. Some standards applied when

testing by EFA are as follows:

Testing the appropriateness of exploratory factor analysis with sample data

through statistical value of Kaiser-Meyer-Olkin (KMO): Accordingly, if the value

of KMO is higher than 0.5, the exploratory factor analysis will be appropriate

(Garson, 2002), whereas if the KMO value is less than 0.5, using exploratory

factor analysis method will not be suitable for existing data.

Number of factors: The numbers of factors are determined based on the

eigenvalue index, which represents the variance explained by each factor.

According to Kaiser’ standards, the factors with eigenvalue less than 1 will be

excluded from the research model (Garson, 2003).

Variance explained: Total variance explained must be greater than 50% (Hair

et al, 1998).

Convergence criterion: To make the scale convergent, the correlation

coefficients between the variables and the coefficients of a factor loading must be

greater than or equal to 0.5 (Gerbing & Anderson, 1988).

Principal component analysis with Varimax rotation: This must be done to

ensure that the number of factors is minimum (Trong and Ngoc 2008).

3.5.4 Building regression function

Scales for factors after tested will be processed Linear Regression by the

method of Ordinary Least Squares (OLS) through two tools of Enter and

Stepwise. Through the regression function, the author will find out the

relationship between the independent variable and dependent variable in the

model.

3.5.5 Testing research hypotheses

Research hypotheses will be tested through actual data from the regression

function. Standards here base on corresponding t-test and p-value (Sig.). The

reliability coefficient is 95%, and p-value will be directly compared with 0.05 to

conclude if the hypothesis accepted or rejected. For testing differences between

sub-total in the study, we use T-test and variance analysis (ANOVA), and also

compare corresponding p-value. To test the appropriation of data and of the

model, we use R-square, t-test and F-test. To evaluate the importance of factors,

we consider corresponding Beta coefficient in the regression function.

3.5.6 Variance analysis

For different tests between subtotals in the study, we use T-test and variance

analysis (ANOVA). This test is also used to directly compare corresponding p-

value. To test the differences between groups of variables, we use Post Hoc Test

with Tukey value to evaluate.

Chapter 4 Research Results

This chapter will present main research results from analysis of actual data with

the support of SPSS 20 software. The analysis contents include: descriptive statistics,

testing the reliability of scales, explore factor analysis, regression analysis, and variance

analysis. The contents in details are as follows:

4.1 Descriptive statistics

From 200 questionnaires which were distributed to employees of Hai Duong

Power Company, the author collected 132 male workers (equivalent to 68%), 62 answer

sheets from female workers (equivalent to 32%). The sample size of 194 questionnaires

ensures the minimum sample size. And the sample structure is based on following

criteria:

4.1.1 Gender

In 194 valid questionnaires, we get 132 male employees (equivalent to

68%), 62 female employees (equivalent to 32%). This exactly reflects the

employee structure of the company as well as characteristics of the industry with

the employee rate between male and female of 70:30.

Figure 5. Sample structure by Gender

4.1.2 Age

From 194 valid questionnaires, if by age classified, the group of employees

at the age from 31 to 35 has largest proportion, accounting for a total of 33% (63

persons), the group at the age from 25 to 30 makes up 22% (43 persons) and the

group at the age from 36 to 40 makes up 21% (41 persons). Other two groups less

than 24 years old and more than 40 years old have proportion of 14% (27 persons)

and 10% (20 persons).

Figure 6. Sample structure by Age

4.1.3 Education level

The results from 194 valid questionnaires show that there are 158 persons at

the university level (equivalent to 81%), 27 persons at college and intermediate

level (equivalent to 14%), and 9 other people are at master level (equivalent to

5%).

Figure 7. Sample structure by Education Level

4.1.4 Work experience

Results from 194 valid questionnaires show that there are 23 employees

working at the company less than 1 year (12%), 62 persons working for the

company less than 5 years with the proportion of 32%, 50 people working for the

company from 5 to 15 years (equivalent to 26%), and 59 persons working for the

company more than 15 years (equivalent to 30%).

Figure 8. Sample structure by year experience

4.2 Results from questionnaire

The research results from questionnaire show that the answer mostly at the level

3 and level 4 in the five point Likert scale. The Mean values are more than 3 and some

questions have Mean value of 5, and the standard deviation is quite small (less than 1).

Therefore, we can initially conclude that the satisfaction level of employees at Hai

Duong Power Company with their job is quite good.

Table 2. The results from questionnaires

N Minimum Maximum Mean Std. D

WO1 194 2.00 5.00 3.3608 .88377

WO2 194 2.00 5.00 3.8402 .81453

WO3 194 2.00 5.00 3.8196 .76411

WO4 194 2.00 5.00 3.8402 .76871

WO5 194 2.00 5.00 3.8093 .78833

WO6 194 2.00 5.00 3.7990 .81806

OP1 194 2.00 5.00 3.7165 .78657

OP2 194 2.00 5.00 3.5567 .76136

OP3 194 2.00 5.00 3.4845 .72145

OP4 194 2.00 5.00 3.9691 .76115

OP5 194 2.00 5.00 3.7732 .70535

SA1 194 2.00 5.00 3.5567 .93818

SA2 194 2.00 5.00 3.5567 .93264

SA3 194 2.00 5.00 3.5412 .93899

SA4 194 2.00 5.00 3.5464 .93322

SA5 194 2.00 5.00 3.6031 .90605

SU1 194 2.00 5.00 3.4845 .72859

SU2 194 1.00 5.00 3.4691 .74914

SU3 194 2.00 5.00 3.5000 .70711

SU4 194 2.00 5.00 3.4330 .67382

CO1 194 2.00 5.00 3.7062 .79589

CO2 194 1.00 5.00 3.7371 .80024

CO3 194 1.00 5.00 3.8144 .76626

CO4 194 2.00 5.00 3.4948 .74977

JS1 194 2.00 5.00 3.5670 .79385

JS2 194 1.00 5.00 3.5773 .84357

JS3 194 1.00 5.00 3.3814 .74727

4.3 Testing the reliability of scales and observed variables in the model

Observed variables in the model are built from 3 to 6 different observed items

for one factor. To test the reliability of scales for factors, we use Cronbach Alpha

coefficient, a popular coefficient used to evaluate the reliability of a research definition

(Suander et al, 2007; Hair et al, 2006). As presented in chapter 3, the standards here

include: Cronbach`s Alpha coefficient must be at least 0.6, the total correlation

coefficient must be at least 0.3. Observed items if have the total correlation coefficient

less than 0.3 will be removed from scales for factor and no appear in next analysis step.

The results from testing the reliability of scales for each factor are as follows:

4.3.1 Testing scales for factor “work”

The factor “work” is built by six observed variables items from WO1 to

WO6. Form actual data, we see that the item WO1 has total correlation coefficient

= 0.0490 less than 0.3. It means the item WO1 is not a scales for factor “work”.

So, we will remove this item from scales for the factor “work”. The results after

item WO1 deleted show Cronbach Alpha coefficient = 0.933 greater than 0.6 and

the total correlation coefficients of observed items are greater than 0.3. Thus, we

can conclude that scales for factor “work” measured by five items from WO2 to

WO6 are reliable and appropriate (table 3).

Table 3. Results from testing scales for factor “work”

CodeCronbach Alpha,

NCorrected Item-

Total CorrelationCronbach's Alpha

if Item Deleted

WO1(removed)

α = 0.933, N = 5

0.049 0.933

WO2 0.807 0.791

WO3 0.832 0.789

WO4 0.824 0.791

WO5 0.724 0.809

WO6 0.754 0.802Note: α is Cronbach Alpha coefficient, N is the number of appropriate items for

factor

4.3.2 Testing scales for factor “promotion opportunities”

The factor “promotion opportunities” is measured by five observed items

from OP1 to OP5. The results from actual data show and the total correlation

coefficients are greater than 0.3 (table 4). So we can conclude that the scales for

factor “promotion opportunities” measured by five observed items from OP1 to

OP5 are reliable and appropriate.

Table 4. Results from testing the scales for factor “promotion opportunities”

CodeCronbach Alpha,

NCorrected Item-Total

CorrelationCronbach's Alpha

if Item Deleted

OP1

α = 0.811, N = 5

.703 .740

OP2 .630 .764

OP3 .618 .769

OP4 .476 .811

OP5 .573 .782Note: α is Cronbach Alpha coefficient, N is the number of appropriate items for

factor

4.3.3 Testing the scales for factor “salary”

The factor “salary” is built from five observed items from SA1 to SA5. The

results from actual data show that Cronbach Alpha coefficient equals to 0.909

>0.6 and the total correlation coefficients are greater than 0.3 (table 5). It proves

that scales for factor “salary” measured by five observed items from SA1 to SA5

are reliable and appropriate.

Table 5. Results from testing scales for factor “salary”

Code Cronbach Alpha, NCorrected Item-Total

CorrelationCronbach's Alpha if

Item Deleted

SA1

α = 0.909, N = 5

.773 .888

SA2 .739 .895

SA3 .813 .880

SA4 .729 .897

SA5 .796 .883Note: α is Cronbach Alpha coefficient, N is the number of appropriate items for

factor

4.3.4 Testing scales for factor “supervisors”

The factor “supervisors” is built by four observed items from SU1 to Su4.

Results from actual data show that Cronbach Alpha coefficient is 0.924 > 0.6, and

the total correlation coefficients of items are greater than 0.3 (table 6). So we can

conclude here that scales for factor “supervisors” measured by four observed

items from SU1 to SU4 are reliable and appropriate.

Table 6. Results from testing scales for factor “supervisors”

Code Cronbach Alpha, NCorrected Item-Total

CorrelationCronbach's Alpha if

Item Deleted

SU1

α = 0.924, N = 4

.851 .891

SU2 .864 .887

SU3 .830 .898

SU4 .751 .924Note: α is Cronbach Alpha coefficient, N is the number of appropriate items for

factor

4.3.5 Testing scales for factor “co-workers”

The factor “co-workers” is built by four observed items from CO1 to CO4.

Results from actual data show that Cronbach Alpha coefficient is 0.816 > 0.6, the

total correlation coefficients of items are greater than 0.3 (table 7). Therefore we

can conclude that scales for the factor “co-workers” measured by four observed

items from CO1 to CO4 are reliable and appropriate.

Table 7. Results from testing scales for factor “co-workers”

Code Cronbach Alpha, NCorrected Item-Total

CorrelationCronbach's Alpha if

Item Deleted

CO1

0.816, N = 4

.668 .754

CO2 .715 .731

CO3 .585 .793

CO4 .581 .794

Note: α is Cronbach Alpha coefficient, N is the number of appropriate items for

factor

4.3.6 Testing scales for the dependent variable “job satisfaction”

The dependent variable “job satisfaction” is measured by three observed

items from JS1 to JS3. Results from data analysis show that Cronbach Alpha

coefficient is 0.793, and the total correlation coefficients of items are greater than

0.3 (table 8). So we conclude that scales for the dependent variable “job

satisfaction” measured by items from JS1 to JS3 are reliable and appropriate.

Table 8. Results from testing scales for the dependent variable “job satisfaction”

Code Cronbach Alpha, NCorrected Item-Total

CorrelationCronbach's Alpha if

Item Deleted

JS1

α = 0.793, N = 3

.613 .742

JS2 .659 .695

JS3 .639 .718Note: α is Cronbach Alpha coefficient, N is the number of appropriate items for

factor

In conclusion, after testing scales for all factors in the model, we see that

there is only one observed item (WO1) in the variable “work” is inappropriate and

removed from factor analysis. Observed variables with Cronbach Alpha

coefficient greater than 0.7 have high reliability level.

4.4 Explore factor analysis

After testing scales for factor by Cronbach`s Alpha coefficient, scales will be

tested by the method of explore factor analysis (EFA). The method of EFA is used to

find the interdependence between the variables. This method will help the author collect

a set of fewer implicit variables (factors) from the data set of observed variables (Hair et

al, 2006). For this study, Explore factor analysis will be done particularly for

independent variables and the dependent variable. Factor extraction method used is

Principal component with Varimax rotation to extract the smallest number of factors

(Hoang Trong and Chu Nguyen Mong Ngoc, 2008). The analysis standards are factor

loading coefficient must be at least 0.5 in one factor, eigen-value equals or greater than

1, variance extracted must be at least 50%, KMO is at least 0.5, Bartlett-test has p-value

less than 0.05. Results from data analysis are as follows:

4.4.1 Explore factor analysis with independent variables

From the data set, item WO1 is consider as a “spam” item and not measures

for the factor “work” (see more in 4.3.1). So doing explore factor analysis with

independent variables, we get following results:

Table 9. KMO and Bartlett's Test with independent variables

Kaiser-Meyer-Olkin Measure of Sampling Adequacy. .865

Bartlett's Test of Sphericity

Approx. Chi-Square 3042.888

df 253

Sig. .000

Table 10. Total variance extracted of independent variables

Component Initial Eigenvalues Rotation Sums of Squared Loadings

Total % of Variance Cumulative % Total % of Variance Cumulative %

1 7.319 31.823 31.823 3.991 17.351 17.351

2 3.912 17.009 48.833 3.782 16.444 33.795

3 2.214 9.627 58.460 3.284 14.277 48.071

4 2.039 8.866 67.326 2.854 12.409 60.480

5 1.115 4.848 72.174 2.689 11.693 72.174

6 .942 4.094 76.268

7 .618 2.685 78.952

8 .584 2.540 81.493

9 .536 2.330 83.823

10 .442 1.920 85.743

11 .414 1.801 87.543

12 .397 1.728 89.271

13 .339 1.476 90.747

14 .322 1.400 92.146

15 .291 1.265 93.412

16 .280 1.216 94.628

17 .258 1.121 95.749

18 .225 .980 96.730

19 .192 .836 97.566

20 .181 .785 98.351

21 .138 .598 98.949

22 .125 .543 99.493

23 .117 .507 100.000

Extraction Method: Principal Component Analysis.

Table 11. Rotated Component Matrix of independent variables

Component1 2 3 4 5

WO4 .885WO3 .874WO2 .855WO6 .805WO5 .800SA3 .873SA5 .873SA1 .861SA2 .831SA4 .807SU2 .901SU3 .866SU1 .863SU4 .833OP1 .739OP5 .735OP2 .722OP4 .632OP3 .623CO1 .791CO2 .779CO4 .662CO3 .653Extraction Method: Principal Component Analysis. Rotation Method: Varimax with Kaiser Normalization.a. Rotation converged in 6 iterations.

The results show that KMO = 0.865 > 0.5, Bartlett-test has p-value = 0.000

< 0.05 (table 9), the variance extracted = 72.174% greater than 50%, eigenvalue =

1.115 after extracting to5 factors (table 10), and observed items form five

different factors (table 11). So, using the method of explore factor analysis is

appropriate to the research data.

4.4.2 Explore factor analysis with the dependent variable “job satisfaction”

From actual data, we do explore factor analysis with the dependent variable

“job satisfaction” and get following results:

Table 12. KMO and Bartlett's Test with the dependent variable

Kaiser-Meyer-Olkin Measure of Sampling Adequacy. .706

Bartlett's Test of SphericityApprox. Chi-Square 173.493df 3Sig. .000

Table 13. Total Variance Explained with the dependent variable

Component Initial Eigenvalues Extraction Sums of Squared LoadingsTotal % of Variance Cumulative % Total % of Variance Cumulative %

1 2.126 70.860 70.860 2.126 70.860 70.8602 .472 15.743 86.6033 .402 13.397 100.000Extraction Method: Principal Component Analysis.

Table 14. Component Matrixa

Component1

JS2 .856JS3 .843JS1 .826Extraction Method: Principal Component Analysis.

The analysis results show that KMO = 0.706 greater than 0.5, Bartlett-test

has p-value = 0.000 less than 0.05 (table 12), eigenvalue equals to 2.126 > 1, the

variance extracted = 70.860% > 50% (table 13), three observed items form only

one factor (table 14). Thus, using method of factor analysis here is appropriate,

and scales for the dependent variable “job satisfaction” are unidirectional scales.

4.5 Building regression function and testing research hypotheses

4.5.1 Estimating regression function from data set

To test research hypotheses, we use method of regression analysis, in which

the factor JS_job satisfaction is a dependent variable and other variables

WO_work, OP_promotion opportunities, SA_salary, SU_supervisors, and CO_co-

worker are independent variables. Variables for regression analysis are

standardized variables using factor score from results of testing explore factor

analysis in the part 4.3. Results from data analysis with SPSS software are as

follows:

Table 15. Model Summaryb

Model R R Square Adjusted R Square

Std. Error of the Estimate

Durbin-Watson

1 .785a .616 .606 .62786456 2.060a. Predictors: (Constant), CO, SU, SA, OP, WOb. Dependent Variable: JS

Table 16. ANOVAa

Model Sum of Squares

df Mean Square

F Sig.

1Regression 118.888 5 23.778 60.316 .000b

Residual 74.112 188 .394Total 193.000 193

a. Dependent Variable: JSb. Predictors: (Constant), CO, SU, SA, OP, WO

Table 17. Coefficientsa

Model Unstandardized Coefficients

Standardized Coefficients

t Sig. Collinearity Statistics

B Std. Error Beta Tolerance VIF1 (Constant) -1.227E-016 .045 .000 1.000

WO .230 .045 .230 5.085 .000 1.000 1.000OP .412 .045 .412 9.109 .000 1.000 1.000SA -.056 .045 -.056 -1.233 .219 1.000 1.000SU .117 .045 .117 2.599 .010 1.000 1.000

CO .614 .045 .614 13.582 .000 1.000 1.000a. Dependent Variable: JS

The regression function is defined as follows: JS = 0.230WO + 0.412OP –

0.056SA + 0.117SU + 0.614CO. Variance analysis shows that F-test has p-value

= 0.000 (table 16), it means there is at least one independent variable having Beta

coefficient differ 0. Adjusted R square = 0.606 (table 15) proves that independent

variables explain 60.6% of the variability of the dependent variable JS-job

satisfaction. Because this study used standardized variables, the estimated model

does not violate the assumptions of the method OLS.

4.5.2 Testing research hypotheses

Testing hypothesis H1: Factor “work itself” positively affects job

satisfaction. From actual data, we see that Beta coefficient of the item WO is β =

0.230 > 0, p-value = 0.000 < 0.05 (table 17). So with the reliability coefficient =

95%, we can suppose that the factor “work” has positive impact on job

satisfaction. In other words, we accept the hypothesis H1. This result shows that

the factor “work itself” is a factor affecting general feeling of employees with job.

If the company finds out solutions to increase satisfaction level with job 1 unit,

the satisfaction level of employees will increase to 0.230 unit.

Testing hypothesis H2: Factor “promotion opportunities” positively affects

job satisfaction. From actual data, we see that Beta coefficient of the item OP is β

= 0.412 > 0, p – value = 0.000 < 0.05 (table 17). So with the reliability coefficient

= 95%, we can suppose that the factor “promotion opportunities” has positive

impact on job satisfaction. In other words, we accept the hypothesis H2. Thi result

once again proves the positive relationship between “promotion opportunities”

and “job satisfaction”. If the chance for promotion is high, the satisfaction level

with job will also become higher. Thus, if the company improves the factor

“promotion opportunities” 1 unit, the satisfaction level with job of employees will

increase to 0.412 unit.

Testing hypothesis H3: Factor “salary” positively affects job satisfaction.

From actual data, we see that the corresponding t-test of the item SA has p – value

= 0.219 > 0.05 (table 17). So with the reliability coefficient = 95%, we can

suppose that the factor “salary” has no impact on job satisfaction. In other words,

we reject the hypothesis H3. At this time, the salary of employees in the field of

electric power in Vietnam and also in Hai Duong is quite good. In comparison

with other fields, the income from this field is much higher than others. The

employees can easily compare in a same request level of working skill, and work

intensity with other companies. So the expectations about salary are not high. We

can consider it as a factor which met expectations of employees already, so it is

not a factor inspiring their satisfaction with job.

Testing hypothesis H4: Factor “supervisors” positively affects job

satisfaction. From actual data, we see that Beta coefficient of the item SU is β =

0.117 > 0, p –value = 0.010 < 0.05 (table 17). So with the reliability coefficient =

95%, we can suppose that the factor “supervisors” has positive impact on job

satisfaction. In other words, we accept the hypothesis H4. This showed that if the

company improves the feeling of employees with the factor “supervisors” (change

leader style, improve the relationship between supervisors and employees) 1 unit,

the satisfaction level of employees with job will increase to 0.117 unit.

Testing hypothesis H5: Factor “co-workers” positively affects job

satisfaction. From actual data, we see that Beta coefficient of the item CO is β =

0.614 > 0, p-value = 0.000 < 0.05 (table 17). So with the reliability coefficient =

95%, we can suppose that the factor “co-workers” has positive impact on job

satisfaction. In other words, we accept the hypothesis H5. This result showed that

the factor “co-workers” has impact on the satisfaction level with job of

employees. If the employees feel satisfied with co-worker relations (for example:

building organizational culture), they will have tendency of becoming more

satisfied with general job. According to this result, if we improve the factor “co-

workers” 1 unit, the job satisfaction level will increase to 0.612 unit.

4.6 Testing the differences between different groups of employees by

demographic variables

To test the differences between employee groups based on demographic variables,

we use analysis methods of T-test and ANOVA. However the variables in the regression

analysis are standardized variables using factor score, so they will not appropriate to be

analyzed by T-test and ANOVA, because standardized variables have equal Variance

and Mean. Therefore, those variables will be encoded according to the rules of taking a

simple average as follows:

ReWO = Mean(WO2,WO3,WO4,WO5,WO6) (variable “work”)

ReOP = Mean(OP1, OP2,OP3,OP4,OP5) (variable “promotion opportunities”)

ReSA = Mean(SA1, SA2, SA3, SA4, SA5) (variable “salary”)

ReSU = Mean(SU1, SU2, SU3, SU4) (variable “supervisors”)

ReCO = Mean(CO1, CO2, CO3, CO4) (variable “co-workers”)

ReJS = Mean(JS1, JS2, JS3) (variable “job satisfaction”).

Results from testing the differences between variables are as follows (here we do

not consider the analysis with observed variable ReSA, because the factor “salary” has

no impact on dependent variable):

4.6.1 Testing differences between variables by gender

To test differences between groups of male and female employees, we use

analysis by Independent T-test, and Levene-test to check the covariance. The

results from analysis of data set are as follows:

Table 18. Statistics by gender group

Gender N Mean Std. Deviation Std. Error Mean

ReWOMale 132 3.7773 .70922 .06173Female 62 3.9161 .68477 .08697

ReOPMale 132 3.7061 .55172 .04802Female 62 3.6871 .59464 .07552

ReSUMale 132 3.4716 .61054 .05314Female 62 3.4718 .71875 .09128

ReCO Male 132 3.6932 .62821 .05468

Female 62 3.6774 .62297 .07912

ReJSMale 132 3.5000 .65835 .05730Female 62 3.5269 .69751 .08858

Table 19. Independent Samples Test

Levene's Test for Equality of Variances

t-test for Equality of Means

F Sig. t df Sig. (2-tailed)

Mean Difference

ReWO

Equal variances assumed

.577 .448 -1.286 192 .200 -.13886

Equal variances not assumed

-1.302 123.369 .195 -.13886

ReOP

Equal variances assumed

1.022 .313 .218 192 .828 .01896

Equal variances not assumed

.212 111.790 .833 .01896

ReSU

Equal variances assumed

4.112 .044 -.002 192 .999 -.00018

Equal variances not assumed

-.002 103.801 .999 -.00018

ReCO

Equal variances assumed

.108 .743 .163 192 .870 .01576

Equal variances not assumed

.164 120.398 .870 .01576

ReJS

Equal variances assumed

.529 .468 -.260 192 .795 -.02688

Equal variances not assumed

-.255 113.478 .799 -.02688

The results show that:

For the variable “work” (ReWO), Levene-test has p-value = 0.448 > 0.05

(table 19), it means the variances between group of male and group of female

employees on the variable “work” are same. Thus, we will use results from “Equal

variances assumed” that shows T-test has p-value = 0.200 > 0.05. It also proves

that there are no significant differences between these two groups on the factor

“work”. The results of the average value also show a very small difference

between them.

For the variable “promotion opportunities” (ReOP), Levene-test has p-value

= 0.313 > 0.05 (table 19), it means the variances between group of male and group

of female employees on the variable “work” are same. Thus, we will use results

from “Equal variances assumed” that shows T-test has p-value = 0.828 > 0.05. It

also proves that there are no significant differences between these two groups on

the factor “promotion opportunities”. The results also show very small average

values of these groups with different gender.

For the variable “supervisors” (ReSU), Levene-test has p-value = 0.044 <

0.05 (table 19), it means the variances between group of male and group of female

employees on the variable “supervisors” are different. Thus, we will use results

from “Equal variances assumed” that shows T-test has p-value = 0.999 > 0.05. It

also proves that there are no significant differences between these two groups on

the factor “supervisors”. The results of the average value also show a very small

difference between them.

For the variable “co-workers” (ReCO), Levene-test has p-value = 0.743 >

0.05 (table 19), it means the variances between group of male and group of female

employees on the variable “supervisors” are same. Thus, we will use results from

“Equal variances assumed” that shows T-test has p-value = 0.870 > 0.05. It also

proves that there are no significant differences between these two groups on the

factor “co-workers”. The results of the average value also show a very small

difference between them.

For the dependent variable “job satisfaction” (ReJS), Levene-test has p-

value = 0.468 < 0.05 (table 19), it means the variances between group of male and

group of female employees on the variable “supervisors” are different. Thus, we

will use results from “Equal variances assumed” that shows T-test has p-value =

0.795 > 0.05. It also proves that there are no significant differences between these

two groups on the factor “job satisfaction”. The results of the average value also

show a very small difference between them.

4.6.2 Testing differences between variables by age

To test differences between groups of different age, we use variance

analysis method (ANOVA). If there are differences between these groups, we

continue using deep analysis method (Post Hoc Test) with Tukey value to test in

which group the differences are. The results from data set are as follows:

Table 20. Variance analysis by age

Sum of Squares

df Mean Square

F Sig.

ReWO

Between Groups

5.258 4 1.314 2.759 .029

Within Groups 90.052 189 .476Total 95.309 193

ReOP

Between Groups

2.408 4 .602 1.927 .108

Within Groups 59.052 189 .312Total 61.460 193

ReSU

Between Groups

3.808 4 .952 2.351 .056

Within Groups 76.536 189 .405Total 80.344 193

ReCO

Between Groups

5.496 4 1.374 3.716 .006

Within Groups 69.886 189 .370Total 75.383 193

ReJS

Between Groups

4.801 4 1.200 2.777 .028

Within Groups 81.685 189 .432Total 86.486 193

The analysis results show that:

For the variable “work”, F-test between groups has p-value = 0.029 < 0.05

(table 20). So, there are differences between groups of different age on the factor

“work”. Results from testing by Tukey value also show differences between group

of employees below 24 years old and group of employees at the age from 25 to 30

and the group at the age from 36 to 40. In details, the group under 24 years old has

tendency of higher satisfaction with job (table 21).

For the variable “co-workers”, F-test between groups has p-value = 0.006 <

0.05 (table 20). It proves that there are differences between groups of different age

on the factor “co-workers”. Results from testing by Tukey value also show

differences between the group of employees under 24 years old and other groups.

In details, the group below 24 years old has tendency of higher satisfaction with

co-workers than others (table 21).

For the variable “job satisfaction”, F-test between groups has p-value =

0.028 < 0.05 (table 20). It proves that there are differences between groups of

different age on the factor “general job satisfaction”. Results from testing by

Tukey value also show differences between the group of employees below 24

years old and and group of employees at the age from 31 to 35 and the group at

the age from 36 to 40. In details, the group under 24 years old has tendency of

higher satisfaction with the factor “job satisfaction” than others (table 21).

For other variables including “promotion opportunities” and “supervisors”,

variance analysis shows that F-test between groups has p-value greater than 0.05,

it means there are no differences between groups of different age on these two

factors.

Table 21. Result from analysis of multi groups by Tukey value

Dependent Variable

(I) IP2 (J) IP2 Mean Difference (I-

J)

Std. Error Sig. 95% Confidence IntervalLower Bound

Upper Bound

ReWO

Below 24

25 – 30 .50508* .16949 .027 .0383 .971931- 35 .37249 .15878 .135 -.0648 .809836 – 40 .49033* .17108 .037 .0191 .9615

Higher 40 .47741 .20364 .136 -.0835 1.038325 - 30 Below 24 -.50508* .16949 .027 -.9719 -.0383

31- 35 -.13260 .13654 .868 -.5087 .243536 – 40 -.01475 .15067 1.000 -.4297 .4002

Higher 40 -.02767 .18683 1.000 -.5422 .4869

31- 35

Below 24 -.37249 .15878 .135 -.8098 .064825 – 30 .13260 .13654 .868 -.2435 .508736 – 40 .11785 .13851 .914 -.2636 .4993

Higher 40 .10492 .17716 .976 -.3830 .5929

36 - 40

Below 24 -.49033* .17108 .037 -.9615 -.019125 – 30 .01475 .15067 1.000 -.4002 .429731- 35 -.11785 .13851 .914 -.4993 .2636

Higher 40 -.01293 .18827 1.000 -.5315 .5056

Higher 40

Below 24 -.47741 .20364 .136 -1.0383 .083525 – 30 .02767 .18683 1.000 -.4869 .542231- 35 -.10492 .17716 .976 -.5929 .383036 – 40 .01293 .18827 1.000 -.5056 .5315

ReCO

Below 24

25 – 30 .44035* .14931 .029 .0291 .851631- 35 .37169 .13987 .064 -.0136 .756936 – 40 .54359* .15071 .004 .1285 .9587

Higher 40 .51157* .17940 .038 .0175 1.0057

25 - 30

Below 24 -.44035* .14931 .029 -.8516 -.029131- 35 -.06866 .12029 .979 -.4000 .262636 – 40 .10323 .13273 .937 -.2624 .4688

Higher 40 .07122 .16458 .993 -.3821 .5245

31- 35

Below 24 -.37169 .13987 .064 -.7569 .013625 – 30 .06866 .12029 .979 -.2626 .400036 – 40 .17189 .12202 .623 -.1642 .5080

Higher 40 .13988 .15607 .898 -.2900 .5697

36 - 40

Below 24 -.54359* .15071 .004 -.9587 -.128525 – 30 -.10323 .13273 .937 -.4688 .262431- 35 -.17189 .12202 .623 -.5080 .1642

Higher 40 -.03201 .16585 1.000 -.4888 .4248

Higher 40

Below 24 -.51157* .17940 .038 -1.0057 -.017525 – 30 -.07122 .16458 .993 -.5245 .382131- 35 -.13988 .15607 .898 -.5697 .290036 – 40 .03201 .16585 1.000 -.4248 .4888

ReJS Below 24 25 – 30 .35716 .16143 .180 -.0874 .801831- 35 .43739* .15122 .034 .0209 .8539

36 – 40 .51069* .16294 .017 .0619 .9595Higher 40 .37654 .19395 .299 -.1577 .9107

25 - 30

Below 24 -.35716 .16143 .180 -.8018 .087431- 35 .08023 .13004 .972 -.2780 .438436 – 40 .15353 .14350 .822 -.2417 .5488

Higher 40 .01938 .17793 1.000 -.4707 .5095

31- 35

Below 24 -.43739* .15122 .034 -.8539 -.020925 – 30 -.08023 .13004 .972 -.4384 .278036 – 40 .07330 .13191 .981 -.2900 .4366

Higher 40 -.06085 .16873 .996 -.5256 .4039

36 - 40

Below 24 -.51069* .16294 .017 -.9595 -.061925 – 30 -.15353 .14350 .822 -.5488 .241731- 35 -.07330 .13191 .981 -.4366 .2900

Higher 40 -.13415 .17931 .945 -.6280 .3597

Higher 40

Below 24 -.37654 .19395 .299 -.9107 .157725 – 30 -.01938 .17793 1.000 -.5095 .470731- 35 .06085 .16873 .996 -.4039 .525636 – 40 .13415 .17931 .945 -.3597 .6280

*. The mean difference is significant at the 0.05 level.

4.6.3 Testing differences between groups by education level

To test differences between groups of different education level, we use

variance analysis method and get following results:

Table 22. Variance analysis by education level

Sum of Squares

df Mean Square

F Sig.

ReWOBetween Groups .116 2 .058 .116 .891Within Groups 95.194 191 .498Total 95.309 193

ReOPBetween Groups .664 2 .332 1.043 .354Within Groups 60.796 191 .318Total 61.460 193

ReSUBetween Groups 1.185 2 .592 1.429 .242Within Groups 79.159 191 .414Total 80.344 193

ReCOBetween Groups .098 2 .049 .124 .883Within Groups 75.285 191 .394Total 75.383 193

ReJSBetween Groups 1.131 2 .566 1.266 .284Within Groups 85.354 191 .447Total 86.486 193

The analysis results show that F-test between groups on every variables has

p-value greater than 0.05 (minimum with the variable ReSU = 0.242). It proves

that there are no differences between employee groups of different education

level.

4.6.4 Testing differences between groups by work experience

To test the differences between groups based on the number of work year of

employees, we use variance analysis method and get following results:

Table 23. Variance analysis by work year

Sum of Squares

df Mean Square

F Sig.

ReWOBetween Groups .413 3 .138 .276 .843Within Groups 94.896 190 .499Total 95.309 193

ReOPBetween Groups 1.369 3 .456 1.443 .232Within Groups 60.091 190 .316Total 61.460 193

ReSUBetween Groups .665 3 .222 .528 .663Within Groups 79.679 190 .419Total 80.344 193

ReCOBetween Groups 2.297 3 .766 1.991 .117Within Groups 73.085 190 .385Total 75.383 193

ReJSBetween Groups 2.983 3 .994 2.262 .083Within Groups 83.503 190 .439Total 86.486 193

The analysis results show that F-test between groups for all variables has p-

value greater than 0.05 (minimum for the variable ReJS which has p –value =

0.083). So, we can suppose that there are no meaningful differences between

groups of different work year on every variables in the model.

4.7 Discussion

The research results show a close relation between factors in JDI model (except

the factor “salary”) and the dependent variable “general job satisfaction”. In this study,

the factor “co-workers” has biggest impact intensity. This result is similar with

conclusions from the research of Madison (2000 quoted from Luddy, 2005) which also

show the factor “co-workers” is one of factors most strongly affecting job satisfaction of

employees. However it is different from research results of Ha Nam Khanh Giao (2011)

in the field of drinking water production (Tan Hiep Phat Corporation). The study of Ha

Nam Khanh Giao proves that the factor “co-workers” has no statistical meaning when

testing its impact on job satisfaction. When comparing characteristics of these two

research units, there are significant differences between the study of Ha Nam Khanh

Giao and this study. The study of Ha Nam Khanh Giao is done in an enterprise with

private capital. For production workers, their job bases on the production line with a

specific assignment. Therefore, relations between co-workers on professional are

mandatory and considered as must-have feature. In this study, Hai Duong Power

Company is an enterprise with state capital, and the sharing of work between co-

workers is limited, so employees care more about factor “co-workers”. This will affect

the satisfaction of employees with job. The second important factor is “promotion

opportunities”. This result is also same with results from some other studies (Ha Nam

Khanh Giao, 2011; Chau Van Toan, 2009; Luddy, 2005; Ellickson and Logsdon, 2002).

This once again confirms the relationship between the organization and job satisfaction.

The third important factor is “work”. This result is similar with expected relationship

between variables in the model. It proves positive relationship between nature of work

and general job satisfaction. And the last important factor is “supervisors”. The research

results also show that job satisfaction is affected by this factor. It is also similar with

results from studies of Robbin et al (2002), Luddy (2005), Tran Kim Dung (2005), Chau

Van Toan (2009) which show positive relationship between job satisfaction and the

factor “supervisors”. In this study, the factor “salary” has no impact on job satisfaction

of employees. It proves results from Bassett (1999 quoted from Luddy, 2005) supposing

that factor salary or income has no significant influence on the satisfaction of employees

with job.

For demographic variables affecting job satisfaction of employees, the research

results show that:

For the variable “gender”, all variables in the model show no differences between

groups of male and female employees on general job satisfaction. This also proves that

perceptiveness levels of male and female employees on job satisfaction are quite same.

The reason may come from the fact that recently, Hai Duong Power Company has good

modes and policies for employees, and there is no phenomenon of discrimination

against male and female workers.

For the variable “age”, the research results show that about the variables “job

satisfaction”, “promotion opportunities”, and “supervisors”, feeling of employees

between groups of different age is quite similar with each other. However, for the factor

“work” and “co-workers”, there are differences between group of employees under 24

years old and others. This group has tendency of higher satisfaction level. The reason

comes from the fact that young employees often tend to integrate more quickly to new

environments, and working environment for staffs is quite friendly so they tend to be

more satisfied than with the factor “co-workers”. Besides, young employees now still

tend to work in state enterprises, particularly at the present when the economic has

many difficulties. So, working in appropriate work places such as Hai Duong Power

Company will make employees feel more satisfied with old people.

For the variable “education level”, the results also significant differences between

groups of different education level on all research factors. Because the education level

of employees resemble each other. Employees at the company are mostly at college and

university level. For In contrast, for the factor working year, the results show no

differences between employee groups having different working year.

Chapter 5 Conclusions and Recommendations

This chapter will present main conclusions of the study, some recommendations,

contributions and the importance of the research. At the same time, the author also

points out limitations as well as directions for further researches in the same field. The

contents in detail are as follows:

5.1 Conclusions

The main purpose of this study is to test the relationship between aspects of work

and general satisfaction with job of employees. The research results show that there are

four in five factors in JDI model have impact on job satisfaction including: (1) work, (2)

promotion opportunities, (3) supervisors, and (4) co-workers. The factor “salary” has no

clear influence on job satisfaction of employees. For factors affecting job satisfaction,

the factor “co-workers” has strongest impact intensity, next is the factor “promotion

opportunities”, the factor “work”, and last is the factor “supervisors” with smallest

impact intensity. For the demographic variables such as gender, age, education level, the

results also show no differences between employee groups. The factor “promotion

opportunities” and “work”, the study show differences between group of young

employees and group of old employees. About the level of job satisfaction, the

assessment values are quite good. This proves that employees now feel quite satisfied

with their job at Hai Duong Power Company.

5.2 Recommendations from research results

The research results show that there are four in five factors in JDI model have

impact on job satisfaction of employees. These results also suggest solutions for

managers to improve the satisfaction level of employees with job by improving

assessment to each factor. Some suggestions from results are as follows:

To increase the satisfaction level of employees, firstly it is needed to concentrate

on the factor “work”. Labor layout must conform to professional competence of

employees, and work must create moderately challenging but stimulating properties.

To increase the satisfaction level on job, it is also needed to improve feeling of

employees with the factor “co-workers”. This requires building corporate culture,

building a spirit of cooperation in the parts of the company. The employee must make a

friendly and mutual trust in the relationship of colleagues in work. The creation of a

work environment of mutual cooperation needs to build a completed and appropriate

workflow, and there is a clear division of work for employees.

Thirdly, it is needed to increase the satisfaction level of employees with the factor

“promotion opportunities”. Promotion policies of the company need to base on the

actual performance of the employees, and to create incentives for healthy competition

among employees with each other. Opportunities created between individuals must

ensure the fairness.

And the last, it is needed for the company to concentrate on the factor

“supervisors”. The leadership in the department should be oriented leadership style of

democracy instead authoritarian style. The supervisor creates trust and support staff in

their work, as well as fair treatment of employees

5.3 The importance of the study

Academically, this study proves that JDI model is a reliable model in measuring

job satisfaction of employees. In five factors of the model, there are four affecting the

satisfaction with job of employees. Practically, the study suggests some solutions for

improving the satisfaction level of employees with job.

5.4 Limitations of the study

Firstly, due to the limitation of time and cost, the author does not still make a deep

interview after the quantitative research to detect “inside” information, the deep nature

of conclusions of the study by close questions.

Secondly, the study uses Non-probability sampling, so the author still does not

evaluate all measurement errors from the sampling method. Hence the conclusions may

have certain limitations.

Thirdly, the study is done in a time-point, so it has not many basics to evaluate

changing tendencies for research issues.

5.5 Directions for future researches

Firstly, it is needed to expand sample size. It means further researches should

extend the investigation scale to increase the reliability of the research model, and to

adjust the suitability of the scales. Further researches can also use the probability

sampling method to increase the representative and generality of the research model.

Secondly, further researches should be done in different times and analyze the

research model in the long-run in order to assess how the measures impact on factors in

the mode.

Thirdly, implementation both quantitative and qualitative research methods by

statistical techniques such as deep interview to detect inside information from

employees

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Appendix

APPENDIX 01 QUESTIONNAIRE

This questionnaire aims to evaluate and analyze the satisfaction level with job and other

factors affecting job satisfaction of employees at Hai Duong Power Company. You

please fill in following sheet.

Starting with:

Part I: Personal information

Name: Date: 2013

1. Gender

Male Female

2. Age

Under 24 25-30 31-35

36〜40 Above 40

3. Education level

College University Master

4. Work experience

Less than 1 year 1 – 5 year

6 – 15 year Above 15

No. Contents of questions

Tot

ally

dis

agre

e

Dis

agre

e

Neu

tral

Agr

ee

Tot

ally

agr

ee

I Work itself

1 WO1The work suits the capacity and professional knowledge 1 2 3 4 5

2 WO2 Clear understanding of the work 1 2 3 4 5

3 WO3 The work allows chance for development of individual 1 2 3 4 5

ability

4 WO4 There is motivation for creative work 1 2 3 4 5

5 WO5 The work is interesting and challenging 1 2 3 4 5

6 WO6 Work assignments are reasonable 1 2 3 4 5

II Promotion opportunities

8 OP1 Fully professional trained 1 2 3 4 5

9 OP2 Opportunities to improve the professional skills 1 2 3 4 5

10 OP3 Create opportunities for those who can afford 1 2 3 4 5

11 OP4 Chance for individual developments 1 2 3 4 5

12 OP5 Training and promotion policies are clear 1 2 3 4 5

III Salary /pay

13 SA1Salary is in accordance with the capabilities and contributions 1 2 3 4 5

14 SA2 Fair rewards for effective work 1 2 3 4 5

16 SA3Equitable distribution of salaries, bonuses and allowances for the contributions 1 2 3 4 5

17 SA4 Can live on current income 1 2 3 4 5

18 SA5 Salary is equal to other units 1 2 3 4 5

IV Supervisors

19 SU1 Supervisors take care of subordinates 1 2 3 4 5

20 SU2 Employees obtain supports from supervisors 1 2 3 4 5

21 SU3 Supervisors fairly treated every employees 1 2 3 4 5

22 SU4Supervisors has good performance, vision as well as leadership skill 1 2 3 4 5

V Co-workers

23 CO1 Co-workers are ready to help each other 1 2 3 4 5

24 CO2 Co-workers coordinate to work well 1 2 3 4 5

25 CO3 Co-workers are very friendly 1 2 3 4 5

26 CO4 co-workers are very trustworthy 1 2 3 4 5

VII General satisfaction

1 JS1 Feel satisfied working here 1 2 3 4 5

2 JS2 Feel happy when be chosen to work here 1 2 3 4 5

3 JS3 Consider the company as the second home 1 2 3 4 5

Thank you very much!