Validity
The extent to which a psychological assessment measures what it claims to measure.
Plain-language definitions of key terms used in psychological assessment — validity, reliability, Cronbach's alpha, subscales, and more.
The extent to which a psychological assessment measures what it claims to measure.
The consistency of an assessment's results across repeated administrations and across items.
A statistical measure of how internally consistent the items on a scale are; ≥ 0.7 is typically acceptable.
A group of items within a larger assessment that measures one specific facet of the overall construct.
An ordered response format (often 5- or 7-point) for rating agreement, frequency, or intensity.
The degree to which items on a scale correlate with one another, suggesting they measure the same construct.
The consistency of an assessment's results when the same person takes it twice, separated by time.
Evidence that an assessment actually measures the abstract concept (construct) it claims to measure.
An assessment format in which respondents rate their own thoughts, feelings, or behaviors.
A specific value on an assessment used to classify respondents into categories. Not a diagnosis.
Whether an assessment appears, on the surface, to measure what it claims to — based on inspection rather than statistical evidence.
Whether the items on an assessment cover the full content domain of the construct being measured.
Whether scores on an assessment correlate with a meaningful external outcome — the criterion.
Evidence that an assessment correlates strongly with other measures of the same construct.
Evidence that an assessment does NOT correlate strongly with measures of unrelated constructs.
The consistency of scores when different raters or observers evaluate the same responses, behaviors, or material.
An estimate of how much a person's observed score is expected to vary from their true score due to measurement error.
Reference distributions of scores from a defined population, used to interpret an individual's score in context.
Administering, scoring, and interpreting an assessment under uniform conditions, with reference norms from a defined sample.
The percentage of scores in a reference group that fall at or below a given score.
The direct, untransformed score from an assessment — typically the sum of item responses.
A standardized score with a mean of 50 and a standard deviation of 10, commonly used in psychological testing.
A standardized score expressing how many standard deviations a raw score is from the mean.
A symmetric, bell-shaped probability distribution that describes how many psychological traits are spread across a population.
A family of statistical methods for identifying the underlying latent factors that explain correlations among observed items.
The tendency of respondents to answer in ways that present themselves favorably rather than accurately.
The tendency of respondents to agree with statements regardless of content, inflating scores on positively worded items.
Systematic ways respondents answer items that aren't driven by item content — patterns like agreeing-with-everything or always picking the middle.
An item worded so that endorsement indicates the opposite of the construct being measured; its score is flipped during calculation.
An item format that asks respondents to choose between options designed to be equally desirable, reducing social desirability effects.
When too many respondents score at or near the maximum, the assessment can't distinguish between them or detect further increase.
When too many respondents score at or near the minimum, the assessment can't distinguish between them or detect further decrease.
The proportion of true cases that an assessment correctly identifies — also called the true positive rate.
The proportion of true non-cases that an assessment correctly identifies as negative — also called the true negative rate.
Using a brief assessment to identify people who may benefit from further evaluation — not to diagnose.
A quantitative measure of the magnitude of a difference or relationship — independent of sample size.