Chapter 2 Research Methodology Chapter 2 Research
Methodology
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2.1 What Is Scientific Inquiry ( ) ? 0 0 0
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What Is Scientific Inquiry? 0 Psychologists study the what,
how, where, when, and why of behavior and mental processes 0
Scientific inquiry utilizes the scientific method 0 More objective
than casual observations 0 Systematic : Procedures follow orderly
steps that are carefully planned 0 Free from bias
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The Scientific Method Depends on Theories, Hypotheses, and
Research The scientific method has three essential elements: 0
Theory( ): interconnected ideas or concepts used to explain prior
observations and to make predictions 0 Hypothesis( ): a testable
prediction about the outcome that would best support the theory 0
Research( ): the systematic and careful collection of data
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Theories Should Generate Hypotheses 0 A good theory produces a
wide variety of testable hypotheses : - J. Piagets theory of infant
and child development generated thousands of hypotheses and
scientific papers - S. Freuds theory that dreams served a wish
fulfillment function generated few testable hypotheses
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Three Mountain Problem
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Unexpected Findings Can Be Valuable 0 Many significant
scientific findings are the result of serendipity : 0 Late 1950s:
Physiologists Wiesel & Hubel hypothesized certain brain cells
in cats would respond when cats looked at dots on slides 0 They
discovered that the cells respond to lines and edges, not dots
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Wiesel & Hubel
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2.2 What Types of Studies Are Used in Psychological Research? 0
Distinguish between descriptive studies , correlational studies ,
and experiments 0 List the advantages and disadvantages of
different research methods 0 Explain why random sampling and random
assignment are important when conducting research studies
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What Types of Studies Are Used in Psychological Research?
Construct ( ) / Variable( ) Theoretical Level/Empirical Level
Conceptual definition/Operational definition e.g. e.g.
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Descriptive Studies Involve Observing and Classifying Behavior
0 Descriptive studies: Involve observing and noting the behavior of
people or other animals to provide a systematic and objective
analysis of behavior 0 Naturalistic observation : passive
observation 0 Participant observation / : 0 : active involvement 0
Developmental designs 0 Longitudinal 0 Cross-sectional
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Observer Bias 0 Observer bias : systematic errors in
observation that occur because of an observers expectations ?? 0
Experimenter expectancy effect 0 Example: Expectations altered how
students treated rats, which influenced the speed at which the rats
learned to run a maze. The students were not aware of their biased
treatment of the animals (Rosenthal & Fode, 1963)
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Correlational Studies Examine How Variables Are Related 0
Correlational studies : examine how variables are naturally related
in the real world 0 Researchers do not attempt to alter variables 0
Researchers cannot draw causal conclusions ( )from correlational
studies 0 Causal vs. Casual
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Directionality Problem 0 Directionality problem: Researchers
find a relationship between two variables but cannot determine
which variable may have caused changes in the other variable 0
Example: Sleep (A) and stress (B) are correlated, but 0 Does less
sleep cause more stress? (A B) 0 Does more stress cause less sleep?
(B A)
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Third Variable Problem 0 Third variable problem: Researchers
cannot be confident that an unmeasured variable is not the actual
cause of differences in the variables of interest 0 Example:
Drinking before driving (A) is correlated with being distracted
while driving (B) 0 Stress (C) causes some people to drink before
driving (C A) 0 Stress (C) causes some people to be distracted
while driving (C B)
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Ethical Reasons For Using Correlational Designs 0 Some research
questions require correlational research designs for ethical
reasons( ) 0 Example: 0 Do soldiers who experience severe trauma
during combat have more difficulty learning new tasks after they
return home compared to soldiers who have experienced less-severe
trauma? 0 It would be unethical to induce trauma in some soldiers
so that you could compare the different groups
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Making Predictions 0 By establishing correlations between
variables, researchers are able to make predictions 0 Example: 0
Correlational research has identified a strong relationship between
depression and suicide 0 Clinical psychologists often assess
symptoms of depression to determine suicide risk 0 ?How to predict
based on the correlation?
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An Experiment Involves Manipulating Conditions 0 Experiment:
Researcher manipulates one variable to examine its effect on a
second variable 0 Independent variable( / ): variable that is
manipulated 0 Dependent variable : variable that is measured 0
Experimental group : the treatment groups that receive the
intervention 0 Control group : a comparison group that does not
receive the intervention (or receives one unrelated to the
independent variable)
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Examining Causality 0 The independent variable is assumed to be
the cause of any change in the dependent variable 0 Such a
conclusion assumes rigorous control 0 Researchers must minimize the
possibility that anything other than the independent variable will
affect an experiments outcome 0 A confound ( )is anything other
than the independent variable that affects a dependent
variable
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Random Sampling and Random Assignment Are Important for
Research 0 Psychologists want to generalize findings from a sample
of individuals to the population of people beyond the study 0
Random sampling( ): Every person in the population has an equal
chance of being selected; most researchers use a convenience sample
0 External validity( ): the degree to which the findings can be
generalized ( )outside the laboratory
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Selection Bias 0 Selection bias( / ): Groups are not equivalent
because participants in different groups differ in unexpected ways
that affect the dependent variable 0 Example: In a study of the
effects of alcohol, one group is assigned to drink tonic water;
another group is assigned to drink alcohol 0 How would you know if
the people in the different conditions of the study are
equivalent?
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Random Assignment 0 You can never be sure that you have
assessed all possible factors that may differ between the groups 0
Random assignment : Each research participant has an equal chance
of being assigned to any level of the independent variable 0 Random
assignment balances ( )out known and unknown factors, increasing
the likelihood that the groups are equivalent
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2.3 What Are the Data Collection Methods of Psychological
Science? 0 Distinguish between five methods of data collection( ) 0
List the advantages and disadvantages of different methods of data
collection 0 Discuss the use of animal models in psychological
research 0 Identify ethical issues associated with psychological
research
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What Are the Data Collection Methods of Psychological Science?
0 Researchers must choose a data collection method 0 The first step
is to determine the level of analysis a particular question is
addressing (biological, individual, social, cultural)
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What Are the Data Collection Methods of Psychological Science?
0 Data collection methods must be appropriate for questions at a
particular level of analysis 0 Culturally sensitive research:
studies that take into account the role that culture plays in
determining thoughts, feelings, and actions
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Observing Is an Unobtrusive Strategy 0 Observational
techniques: systematic assessment and coding of overt behavior 0
Should the study be conducted in the laboratory or in a natural
environment? 0 How should the data be collected?
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Observing Is an Unobtrusive Strategy 0 Should the observer be
visible? 0 Reactivity( ): Presence of the observer alters the
behavior of those being observed 0 The Hawthorne Effect
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Case Studies Examine Individual Lives and Organizations 0 Case
study( ): intensive examination of unusual people or organizations
0 Examples: 0 The goal of an organizational case study is to
determine which practices led to success or failure 0 Case studies
of people with psychological disorders are the type used most
frequently in psychology 0 Problems: Case studies are subjective
and have a small sample size
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Asking Takes a More Active Approach 0 Compared to observation,
asking people about themselves is a more interactive way of
collecting data 0 Self-report methods such as questionnaires or
surveys are used to gather data from a large number of people in a
short time 0 Interviews( ) 0 Experience sampling
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Self-Report Bias 0 Problem with asking-based methods of data:
Its difficult to discern an honest or true response 0 Socially
desirable responding( )/faking good: Person responds in a way that
is most socially acceptable 0 Better-than-average effect : People
tend to describe themselves in positive ways that are not
necessarily true
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Response Performance Measures the Processing of Information 0
Response performance : Researchers quantify perceptual or cognitive
processes in response to a specific stimulus 0 Three major types: 0
Reaction time 0 Response accuracy 0 Stimulus judgments
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Body/Brain Activity Can Be Measured Directly 0
Psychophysiological assessment( ): Researchers examine how bodily
functions (physiology) change in association with behaviors or
mental states (psychology) 0 A polygraph measures physiological
activity (e.g., heart rate, perspiration rate, blood pressure)
related to behaviors or mental states
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Electrophysiology( ) 0 Electrophysiology: data collection
method that measures electrical activity in the brain 0
Electroencephalograph (EEG ):a device that measures brain activity
0 Produces electroencephalograms, which reflect all brain activity;
are too noisy or imprecise to isolate specific responses to
particular stimuli 0 Event-related potential (ERP ): By averaging
across many trials, brain activity in response to a specific
stimulus can be observed
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Brain Imaging 0 Positron emission tomography (PET ): provides a
computer-aided reconstruction of the brains metabolic activity by
tracking a radioactive substance 0 Magnetic resonance imaging
(MRI): A scanner produces a powerful magnetic field that the
tissues in the brain respond to 0 Functional magnetic resonance
imaging (fMRI): measures blood flow indirectly by assessing changes
in the bloods oxygen level
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Transcranial Magnetic Stimulation 0 Transcranial magnetic
stimulation (TMS ): A very fast, powerful magnetic field disrupts
brain activity momentarily in a specific brain region 0 Example:
Placing a TMS coil over areas of the brain involved in language
will temporarily disrupt a persons ability to speak 0 Powerful
method for examining which brain regions are necessary for specific
psychological functions
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Research with Animals Provides Important Data 0 Many important
research findings in psychology have been obtained by studying the
behavior of nonhuman animals 0 Forces that control the behaviors of
all animals exert their effects in similar ways 0 For ethical
reasons, some research cannot be conducted with humans 0 Transgenic
mice are produced by manipulating the genes in developing mouse
embryos
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There Are Ethical Issues to Consider 0 When scientists select a
research method, they must know the ethical issues involved 0 They
must also adhere strictly to the relevant ethical guidelines
maintained by all colleges, universities, and research institutes 0
Institutional review boards (IRBs): review all proposed research to
ensure that it meets scientific and ethical standards
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Privacy 0 Privacy is a prominent ethical concern 0 Is it okay
to observe people without their knowledge? 0 When people are asked
for information, should some topics not be raised because they may
be too personal or otherwise inappropriate? 0 Researchers must
consider how observation and questioning may affect the individuals
they are studying
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Access to Data 0 Researchers must consider who will have access
to the data they collect 0 Participant confidentiality should
always be guarded carefully so that personal information is not
linked publicly to a studys findings 0 The quality and accuracy of
data often depend on participants certainty that their responses
will be kept confidential 0 Anonymity is not the same as
confidentiality
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Informed Consent 0 People who volunteer for psychological
research have the right to know what will happen to them during the
course of the study 0 Ethical standards require informed consent:
People are given all relevant information that might affect their
willingness to participate 0 If deception is used, a careful
debriefing must take place after the studys completion
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Relative Risks of Participation 0 Researchers have to think
carefully about the potential for risk to participants 0
Institutional Review Boards (IRBs) look at the relative trade-offs
between risk and benefit 0 The risk/benefit ratio / is an analysis
of whether the research is important enough to warrant placing
participants at risk
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2.4 How Are Data Analyzed and Evaluated? 0 Identify three
characteristics that reflect the quality of data 0 Describe
measures of central tendency and variability 0 Describe the
correlation coefficient 0 Discuss the rationale for inferential
statistics
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2.4 How Are Data Analyzed and Evaluated? 0 What characteristics
make data good? 0 What are some of the statistical procedures that
researchers use to analyze data?
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Good Research Requires Valid, Reliable, and Accurate Data 0
Internal validity: Do the data collected address your question? 0
Reliability: Do the data collected vary substantially over time? 0
Accuracy: Is the measure from which the data are derived error
free? 0 Random error: Amount of error introduced into each
measurement differs each time 0 Systematic error: Amount of error
introduced into each measurement is constant
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Descriptive Statistics Provide a Summary of the Data 0 The
first step in evaluating data is to inspect the raw values for
errors in data recording 0 Then, data are summarized using
descriptive statistics 0 Central tendency: describes a typical
response (mean, median, mode) 0 Variability: describes how widely
dispersed the values are about the mean (standard deviation)
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Correlations Describe the Relationships between Variables 0
Descriptive statistics can also be used to summarize how two
variables relate to each other 0 The first step in examining the
relationship between two variables is to create a scatterplot 0
correlation coefficient: a statistical value between 1.0 and +1.0
indicating the type (negative/positive) and strength of the
relationship between two variables
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Inferential Statistics Permit Generalizations 0 Inferential
statistics: used to determine whether differences actually exist in
the populations from which samples were drawn 0 Inferential
statistical techniques are used to determine if observed
differences between sample means (e.g., the driving performances of
sober and drunk drivers) are likely due to chance or if they
reflect differences in populations 0 Results deemed unlikely to be
due to chance are statistically significant
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Meta-Analysis 0 Meta-analysis: a type of study that involves
the analysis of multiple analyses 0 With meta-analysis, many
studies that have addressed the same issue are combined and
summarized in one study of studies 0 Because meta-analysis combines
the results of separate studies, many researchers believe that
meta-analysis provides stronger evidence than the results of any
single study