MEASUREMENT IN RESEARCH報告者：許之馨授課老師：任維廉 教授

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自我介紹許之馨

台北人

運管系大四

興趣：看電影、吃美食

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OUTLINE

1. Measurement2. Validity

• Content validity• Criterion-related validity• Construct validity

3. Reliability• Standard error measurement• Internal consistency• Equivalence• Stability

4. Response set

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MEASUREMENT

All descriptive and experimental research studies involve some kind of measurement.

Two related terms Test Evaluation

Formative evaluation Summative evaluation

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VALIDITY

The tools used in descriptive research Test Questionnaires Interview guide

The extent to which a research tool measures what it intends to measure.

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VALIDITY

Three major type Content validity Criterion-related validity Construct validity

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CONTENT VALIDITY

Item in research tool Related to the subject matter tested / stated

objectives of a course of study or program? Reflecting the emphasis placed in a course or a

program? Representative of the universe of items?

Non-statistical

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CONTENT VALIDITY

Test blueprint Two-way chart ( related specific objective to

specific content areas )

http://www.utexas.edu/provost/sacs/pdf/Test%20Blueprint%20handout.pdf

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CRITERION-RELATED VALIDITY

Empirical (statistically)

Comparison the scores on the to-be-validated test and the scores on a criterion measure Correlation coefficient

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CRITERION-RELATED VALIDITY

Concurrent validity The to-be-validated test and the criterion test

were made at same time or after a short interval

Predicative validity A much longer time interval exists between the

two test situations or the two assessment situations

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CONSTRUCT VALIDITY

Construct Psychological traits or characteristic Not directly observable but be inferred on the basis of

overt behavior

To the extent of measuring a theoretical construct or trait

Controversial

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RELIABILITY

The consistency of getting the same or similar responses The accuracy of the score of one person

The person’s score obtained on a test is not the person’s true score

Standard error measurement(SEM)

The consistency of score of a group of people Internal consistency Equivalence Stability

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STANDARD ERROR MEASUREMENT

Test someone with all our tremendous number of equivalent forms. Then we will find that scores are not the same. The distribution of scores familiar are resemble the familiar “ normal ” curve.

The average of scores is his true score.

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STANDARD ERROR MEASUREMENT

The standard deviation as a measure od the variation of observed scores around the true score

SD : standard deviation of obtained scores of a group : the reliability coefficient computed for

the same group

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INTERNAL CONSISTENCY

Reliability derived from the administration of a single test (questionnaire, interview)

Methods of determining reliability correlation coefficient Split half

Divided into two equal halves. Correlation coefficient the of scores of two half-tests. The Spearman-Brown formula to get the reliability of the

entire test

r : reliability of the full testr1/2 : reliability of the two half tests

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INTERNAL CONSISTENCY

Kuder-Richardson

: estimate of reliability based on Kuder-Richardson n : number of items in the test

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EQUIVALENCE

Parallel test form are administration to a group of people at the same time or with very little time lapse.

The correlation coefficient is computed between the scores of the two tests.

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STABILITY

The same test after substantial time lapse

One test version here or now and equivalent test version after substantial time interval

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RESPONSE SET

A consistent tendency to follow a certain pattern in responding to items in a test (questionnaire, interview)

Interference with getting usable data Avoiding extreme response option Socially expected response Faking

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RESPONSE SET

Weaken validity Halo Effect Generosity Error Error of Central Tendency

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Thanks for your attention

Q&A