Guides.

Straight answers to the questions people ask about psychological tests - written from the research literature, not from marketing.

• Big Five vs MBTI: What the Science Actually SaysMBTI types feel right but fail psychometric tests; the Big Five is the research standard. A PhD psychometrician explains the differences honestly - and how your four letters map onto five traits.Read guide
• HEXACO vs Big Five: Do You Need a Sixth Trait?HEXACO adds Honesty-Humility to the five-factor model and reshapes Agreeableness and Emotionality. What the sixth factor predicts, how the models differ, and which test fits your question.Read guide
• How to Tell a Valid Free IQ Test from EntertainmentMost free IQ tests are entertainment. A PhD psychometrician explains the four marks of a real test - classical item formats, population norms, an honest ceiling, transparent limits - and what online scores can and cannot tell you.Read guide