Psychology Chapter 5: Good Measurement

Questions and Answers

Which of the following are ways to measure variables? (Select all that apply)

Statistical

Self-Report (correct)

Observational (correct)

Physiological (correct)

What is a self-report measure?

Operationalizes a variable by recording people's answers to questions about themselves in a questionnaire or interview.

What does an observational measure do?

Operationalizes a variable by recording observable behaviors or physical traces of behaviors.

What is a physiological measure?

Operationalizes a variable by recording biological data such as brain activity, hormone levels, or heart rate. Signup and view all the answers

What are the scales of measurement? (Select all that apply)

Quantitative Variables Signup and view all the answers

What defines categorical variables?

Levels are categories and coded arbitrarily. Signup and view all the answers

Describe quantitative variables.

Levels are meaningful numbers. Signup and view all the answers

What are the three types of quantitative variables?

Ordinal scale, interval scale, ratio scale. Signup and view all the answers

What is an ordinal scale?

Numbers represent ranked order but do not indicate the degree of difference. Signup and view all the answers

What does the interval scale indicate?

Numbers represent equal intervals between levels. Signup and view all the answers

What is a ratio scale?

Has equal intervals and a true '0', indicating none of that variable. Signup and view all the answers

What does reliability refer to in the context of measurement?

How consistent the results of a measure are. Signup and view all the answers

What is validity concerned with?

Whether the operationalization is measuring what it is supposed to measure. Signup and view all the answers

Which of the following are types of reliability? (Select all that apply)

Interrater Reliability Signup and view all the answers

What does test-retest reliability measure?

Consistency of scores every time the measure is used. Signup and view all the answers

What is interrater reliability?

Consistent scores obtained no matter who measures or observes. Signup and view all the answers

What does internal reliability (or internal consistency) ensure?

A study participant gives a consistent pattern of answers. Signup and view all the answers

What is Cronbach's alpha used for?

To assess internal reliability through correlation-based statistics. Signup and view all the answers

Define construct validity.

Measurement reliability plus measurement validity. Signup and view all the answers

What does measurement validity reflect?

How well a measure reflects the construct. Signup and view all the answers

What is the difference between reliability and validity?

Reliability is consistency and validity is accuracy. Signup and view all the answers

What is face validity?

Appears to be a plausible measure of the variable in question; subjective judgment. Signup and view all the answers

What is criterion validity based on?

Objective, empirical evidence. Signup and view all the answers

What is the known groups paradigm?

Researchers determine if scores can discriminate among groups with well-understood behaviors. Signup and view all the answers

Define convergent validity.

A measure should correlate more strongly with other measures of the same construct. Signup and view all the answers

Define discriminant validity.

The measure should correlate less strongly with measures of different but related constructs. Signup and view all the answers

Can a measure be reliable but not valid?

Yes. Signup and view all the answers

Study Notes

Ways to Measure Variables

Three primary measurement methods: self-report, observational, and physiological.

Self-Report Measure

Gathers data by having individuals answer questions in surveys or interviews.
Commonly measures personal attributes like gender, stress, religiosity, motivation, and personality.

Observational Measure (Behavioral Measure)

Captures data by noting observable actions or traces from behaviors.
Examples include assessing intelligence through puzzle-solving or measuring happiness by counting smiles.

Physiological Measure

Involves recording biological indicators such as brain activity, hormone levels, or heart rate.
Techniques include fMRI for brain scanning and facial EMG to detect muscle movements indicating emotions.

Scales of Measurement

Two main categories: categorical and quantitative variables.

Categorical Variables

Comprise discrete categories with no numerical meaning, such as gender or species.
Coded arbitrarily, e.g., 1 for Male and 2 for Female.

Quantitative Variables

Represent measurable quantities with meaningful numerical values, such as height or test scores.

Types of Quantitative Variables

Ordinal scale: ranks order without indicating difference degree.
Interval scale: equal intervals with no true zero, e.g., IQ scores or temperature.
Ratio scale: possesses equal intervals and a true zero, e.g., height or time measurements.

Reliability

Indicates the consistency of measurement results.

Validity

Evaluates whether the measurement accurately reflects the intended variable.

Types of Reliability

Test-retest reliability: Consistency across multiple uses of the same measure.
Interrater reliability: Consistency regardless of who conducts the measurement.
Internal reliability: Consistency of responses among related items within a measure.

Evaluating Reliability with R

Positive correlation (r > 0.5) indicates strong test-retest reliability.
Interrater reliability evaluated with an ideal positive correlation (r > 0.7).

Measuring Internal Reliability

Assessed by the association among items meant to evaluate the same construct, using Cronbach's alpha.

Cronbach's Alpha

A correlation metric used to examine the internal reliability of measures.

Construct Validity

Integrates both measurement reliability and validity.

Measurement Validity

Reflects how effectively a measure represents the intended construct, e.g., assessing self-reported religiosity accuracy.

Reliability vs. Validity

Reliability focuses on consistency, while validity emphasizes accuracy; a measure can be reliable yet not valid.

Valid Measures of Abstract Constructs

Psychologists may operationalize concepts like happiness through varied methods: questionnaires, observation, or biological indicators.

Face Validity

Subjective assessment indicating whether a measure seems plausible; e.g., head circumference as an indicator of hat size appears valid but not for IQ.

Content Validity

Ensures that the measure encompasses all facets of the construct being evaluated.

Criterion Validity

Validity assessed through empirical evidence showing correlation with key outcomes, exemplified by the relationship between SAT scores and college GPA.

Known Groups Paradigm

Evaluates if a measure differentiates between groups with already understood behavior.

Convergent Validity

Measures of the same construct should correlate strongly with each other.

Discriminant Validity

A measure should exhibit weaker correlations with different but related constructs.

Reliability and Validity Relationship

A precise measure can be reliable without being valid; however, validity cannot exceed reliability levels.

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Description

Explore the key concepts of measurement in psychology through flashcards. This quiz covers self-report, observational, and physiological measures, essential for understanding how to quantify and analyze variables effectively.