Glossary

Plain-language definitions of key terms used in psychological assessment — validity, reliability, Cronbach's alpha, subscales, and more.

Validity

The extent to which a psychological assessment measures what it claims to measure.

Reliability

The consistency of an assessment's results across repeated administrations and across items.

Cronbach's alpha (α)

A statistical measure of how internally consistent the items on a scale are; ≥ 0.7 is typically acceptable.

Subscale

A group of items within a larger assessment that measures one specific facet of the overall construct.

Likert scale

An ordered response format (often 5- or 7-point) for rating agreement, frequency, or intensity.

Internal consistency

The degree to which items on a scale correlate with one another, suggesting they measure the same construct.

Test-retest reliability

The consistency of an assessment's results when the same person takes it twice, separated by time.

Construct validity

Evidence that an assessment actually measures the abstract concept (construct) it claims to measure.

Self-report

An assessment format in which respondents rate their own thoughts, feelings, or behaviors.

Cutoff score

A specific value on an assessment used to classify respondents into categories. Not a diagnosis.