Psychometrics & Testing

Validity (Psychometric)

Whether a test measures what it claims to measure. A valid personality test actually predicts real-world outcomes like job performance, relationship satisfaction, or mental health.

Validity is the most fundamental question in psychometrics: does this test actually measure what it says it measures? There are several types of validity.

Construct validity: Does the test measure the theoretical concept accurately? (Big Five: strong. MBTI: moderate. BuzzFeed quizzes: none.) Predictive validity: Does the test predict real-world outcomes? (Big Five Conscientiousness predicts job performance at r=0.20-0.30. RIASEC congruence predicts job satisfaction at r=0.28.) Criterion validity: Do test scores correlate with external measures they should relate to?

A test can be reliable (consistent results) but not valid (measuring the wrong thing). The strongest validated personality frameworks are: Big Five (decades of cross-cultural replication), RIASEC (integrated into O*NET career database), and DISC (extensive corporate validation data).

Related Terms

Test-Retest Reliability

A measure of how consistent a test's results are when the same person takes it again. High reliability (0.70+) means you'll get similar results each time.

Likert Scale

A response format used in personality tests where you rate agreement on a scale (e.g., "Strongly Disagree" to "Strongly Agree"). Named after psychologist Rensis Likert (1932).

Psychometric Test

A standardized, scientifically designed assessment that measures psychological attributes — personality traits, cognitive abilities, aptitudes, or attitudes — in a reliable and valid way.

Cronbach's Alpha

A statistic measuring internal consistency — how closely related a set of test items are as a group. Values above 0.70 indicate acceptable reliability for personality scales.

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