Chapter 4: Measurement Next time: Writing Chapter 9

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Chapter 4 MeasurementNext time Writing
(Chapter 9)
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Miller, C. F., Trautner, H. M., Ruble, D. N.
(2006). The role of gender stereotypes in
childrens preferences and behaviors. In L.
Balter C. S. Tamis-LeMonda (Eds.), Child
psychology A handbook of contemporary issues
(2nd ed., pp. 293-323). New York Psychology
Press.
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Chapter 4 MeasurementNext time Writing
(Chapter 9)
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Operational definition Definition of a variable
in terms of the operations used to produce or
measure the variable
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Stevens Measurement is the assignment of
numbers to aspects of objects or events according
to one or another rule.
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Level of Measurement

• Nominal
• Ordinal
• Interval
• Ratio

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Decisions about Measurement

• How to operationalize
• Which aspects (e.g., frequency, intensity,
  duration)
• Context (field, lab)
• Source (behavior, verbal report)
• Goal (state-trait)

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Measurement equivalence Comparability of
procedures and measurements across the groups
being compared
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ReliabilityValidity
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Reliability Consistency or repeatability of
measurement
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Reliability

• Test-Retest
• Internal Consistency

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Test validity Accuracy with which a test
measures what it is supposed to measure
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Forms of Test Validity

• Content validity
• Criterion validity
• Construct validity

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Convergent Validity
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Convergent ValidityDivergent Validity
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Shared methods variance Similarity among two or
more sets of scores that results from
similarities in the methods used to obtain the
scores
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Multitrait-Multimethod (MTMM) Matrix
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Trait A B C
1 A1 B1 C1 Method 2 A2 B2
C2 3 A3 B3 C3
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RegressionToward the Mean
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Regression toward the mean Tendency of initially
extreme scores to move toward the group mean upon
retesting
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Threats to Validity in Pretest-Posttest Designs

• Regression toward the mean
• Testing
• History
• Maturation

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Mean Time 1 Time 2

• Grads 105 97 ?
• Dropouts 90 97 ?