How we measure — and where the limits are

What the test measures

We measure the “Big Five” — the best-researched model in personality science: emotional sensitivity (neuroticism), extraversion, openness, agreeableness and conscientiousness, each with six facets. Personality is always a continuum: there are no “types” and no boxes — every score is a point on a scale, not a label.

Deliberately NOT on offer: type tests in the style of “16 personalities”. They read nicely, but the type sorting doesn't hold up scientifically — the same person often lands in a different box on retake.

Where the questions come from

The 60 questions are the IPIP-NEO-60 (Maples-Keller et al., 2019, Journal of Personality Assessment) — a short form selected via item response theory from the International Personality Item Pool. The items are public domain and scientifically validated; internal consistency of the five dimensions in the validation study: α = .75–.79 — solid for a 60-question short form; longer instruments (120+ questions) measure more finely but take several times as long.

What you are compared against

Your percentile ranks refer to an open research sample of 231,953 people (English-speaking, international, collected 2001–2011, average age ~26). We computed these norms ourselves from the public raw data and validated the computation against published statistics. Honestly, that also means: the comparison group is younger and more English-speaking than you may be. Once enough results exist in your language (~1,000+), we will switch to language-specific norms — and say so here.

How precise this is

• We only show percentile ranks from 1 to 99 — “better than 100%” doesn't exist in honest statistics.
• The 30 facets are based on 2 questions each. That shows tendencies but is deliberately NOT fine measurement — which is why this note also appears directly in the report.
• Self-report measures your self-image. Daily form, mood and the wish to present a certain side shift results by a few points. Variation on retake is normal.

What this test is NOT

Not a clinical instrument, not a diagnosis, not a basis for therapy. Not suitable and not approved for hiring, promotion or admission decisions. If results weigh on you or you recognise yourself in heavy phases: talking to a professional can do more than any online test.

The business model, stated openly

Your result is free and stays free. We earn money exclusively from the in-depth report (one-time 2.99 €) — no subscription, no data sharing, no ads. If the free result is enough for you, we're still glad you came.