Psychometrics: How Psychological Measurement Actually Works
A test is never valid — an interpretation is. Reliability, validity, standard error, norming and latent variables, explained from the governing Standards.
What IQ is, how IQ tests work, the history and science of intelligence measurement.
25 articles
A test is never valid — an interpretation is. Reliability, validity, standard error, norming and latent variables, explained from the governing Standards.
Howard Gardner's theory of multiple intelligences proposes several distinct intelligences rather than one IQ. The eight intelligences, how it differs from 'g', the criticisms, and why scientists are skeptical.
IQ measures reasoning; EQ measures emotional intelligence. How they differ, how each is assessed, and what the research says about which predicts success.
From Alfred Binet's 1905 scale to modern adaptive testing: the people, milestones and controversies that shaped how we measure intelligence.
A guide to the major IQ tests — WAIS, Stanford-Binet, Raven's Progressive Matrices, culture-fair tests — what each measures and how they differ.
How IQ tests are built and scored: standardization samples, the mean-100/SD-15 scale, item difficulty, reliability and validity — in plain English.
What IQ actually measures, where the concept came from, the g-factor, how modern IQ tests work, and the limits of a single intelligence number.