Research Methods: Measurement and Validity

Flashcards covering key concepts in psychological measurement, including variables, operationalization, scales, reliability, and validity.

What is a conceptual variable?

The researcher
s definition of the variable in question at a theoretical level.

Explain the difference between a conceptual variable and its operationalization.

Conceptual variables are theoretical and subjective, while operationalization represents a researcher's specific decision about how to measure or manipulate the conceptual variable.

What are the three main ways psychologists typically operationalize variables?

Self-report measures, observational measures, and physiological measures.

Describe self-report measures and provide an example.

Self-report measures operationalize a variable by recording people
s answers to questions about themselves in a questionnaire or interview. Example: Diener's five-item satisfaction scale.

Describe observational measures and provide an example.

Observational measures operationalize a variable by recording observable behaviors or physical traces of behaviors. Example: Counting how many times a person smiles.

Describe physiological measures and provide an example.

Physiological measures operationalize a variable by recording biological data, often requiring equipment to analyze brain activity, heart rate, or hormone levels. Example: Using facial electromyography (EMG) for moment-to-moment happiness.

What are categorical measurement scales?

Categorical measurement scales have levels that are categories (nominal variables). Examples: Sex (male, female), nationality (Hispanic, non-Hispanic).

What are quantitative measurement scales?

Quantitative measurement scales have levels that are coded with meaningful numbers.

Describe an ordinal measurement scale.

In an ordinal scale, numerals represent a rank order, but the distance between subsequent numerals may not be equal. Example: A 1-10 'most to least favorite' rating.

Describe an interval measurement scale.

In an interval scale, subsequent numerals represent equal distances, but there is no true zero. Examples: IQ score, shoe size, or degree of agreement on a 1-7 scale.

Describe a ratio measurement scale.

In a ratio scale, numerals represent equal distances, and zero genuinely represents none of the variable being measured. Examples: Number of exam questions answered correctly, height in cm.

What is the primary difference between reliability and validity of a measure?

Reliability refers to how consistent the results of a measure are, and validity refers to whether the operationalization is measuring what it is supposed to measure.

Identify the three types of reliability.

Test-retest reliability, interrater reliability, and internal reliability.

What is test-retest reliability and when is it most relevant?

Test-retest reliability means a study participant will get the same score each time they are measured with it. It is most relevant when measuring constructs (e.g., personality, intelligence) that are theoretically stable.

What is interrater reliability and when is it relevant?

Interrater reliability means consistent scores are obtained no matter who measures the variable. It is relevant for observational measures.

What is internal reliability and when is it relevant?

Internal reliability means a study participant gives a consistent pattern of answers, no matter how the researcher phrases the question. It applies to measures that combine multiple items.

What are scatterplots used for in psychology research?

Scatterplots visually represent the relationship between two quantifiable variables, showing positive, negative, or zero correlations and suggesting the strength of a relationship.

How does the correlation coefficient, r, describe the direction and strength of a relationship?

The slope of r describes the direction (positive 1.0, negative -1.0, or zero). The value of r, which falls between 1.0 and -1.0, indicates strength: closer to 1 or -1 means a strong relationship, closer to zero means a weak relationship.

Define face validity and provide an example.

Face validity is when a measure is subjectively considered to be a plausible operationalization of the conceptual variable. Example: Head circumference has high face validity as a measurement of hat size.

Define content validity and provide an example.

Content validity requires a measure to capture all parts of a defined construct. Example: An IQ test (operationalization of intelligence) should include questions assessing all components of intelligence (e.g., reason, plan, solve problems, learn quickly).

Define criterion validity and provide an example.

Criterion validity assesses whether scores on the measure can discriminate among two or more groups whose behavior is already confirmed. Example: Validating salivary cortisol levels by showing a speech group has higher levels than an audience group.

Define convergent validity and provide an example.

Convergent validity means a self-report measure is strongly associated with other self-report measures of similar constructs. Example: High scores on both the BDI and CES-D depression scales.

Define discriminant validity and provide an example.

Discriminant validity means a self-report measure is less strongly associated with self-report measures of dissimilar constructs. Example: A depression measure should not correlate with overall physical wellness.

Explain the relationship between reliability and validity.

Reliability has to do with how well a measure correlates with itself, while validity concerns how well a measure is associated with something else (e.g., a behavior it indicates). Reliability is necessary but not sufficient for validity.