Sixteen Factor Profile (IPIP-16PF)

What the IPIP-16PF measures

Raymond Cattell's factor-analytic work proposed that the vocabulary people use to describe one another resolves into sixteen primary factors, a finer-grained account than the five broad domains that later became standard. The 16PF Questionnaire itself is a commercial instrument requiring qualified-user licensing. The scales measured here are not that questionnaire: they are the International Personality Item Pool's public-domain scales, constructed to measure constructs similar to Cattell's sixteen, and they carry their own reliabilities rather than inheriting his.

The dimensions it assesses

• Warmth (10 items, IPIP alpha .80)
• Intellect (13 items)
• Emotional Stability (10 items)
• Assertiveness (10 items)
• Gregariousness (10 items)
• Dutifulness (10 items)
• Friendliness (10 items)
• Sensitivity (10 items)
• Distrust (10 items)
• Imagination (10 items)
• Reserve (10 items)
• Anxiety (10 items)
• Complexity (10 items)
• Introversion (10 items)
• Orderliness (10 items)
• Emotionality (10 items)

What to do with your result

1. Read the shape, not the peaks: Sixteen scales produce a profile, and the useful information is which scales sit high relative to your own others, rather than how any one compares to other people, which this cannot tell you.
2. Treat adjacent scales together: Several of these scales overlap conceptually (Gregariousness and Friendliness, Reserve and Introversion). Where two neighbours disagree sharply, that contrast is usually more informative than either alone.
3. Re-take rather than over-read: Personality scales move between sittings. A scale that shifts by a small amount between two attempts has told you it is not a defining feature.

Common questions about the IPIP-16PF

What does the IPIP-16PF measure?

Sixteen primary personality factors, measured by the public-domain IPIP scales built to parallel the constructs in Cattell's 16PF Questionnaire.

Can the IPIP-16PF diagnose me?

No. Sixteen Factor Profile (IPIP-16PF) is a screening questionnaire, not a diagnostic tool. It can flag that something may need a closer look. It cannot tell you what is causing it. It describes tendencies rather than diagnosing anything, and no result here is a condition or something to fix.

How long does the IPIP-16PF take?

163 questions, which most people finish in 25 – 35 minutes. There is no time limit, and answering honestly matters more than answering quickly. The results page checks for patterns suggesting the questions were rushed.

Is this IPIP-16PF test really free?

Yes. No account, no email address, no payment. Psychometrics Today is funded by donations rather than advertising, which is also what allows us to publish instruments whose authors permit free but non-commercial use.

Are my answers stored or shared?

No. Your answers are scored inside your browser and never sent to us. There is no database of responses, because we never receive any. Closing the tab erases them, which is why results cannot be recovered afterwards.

How often should I retake the IPIP-16PF?

Traits and preferences move slowly, so retaking this every few months is more informative than retaking it often. Larger shifts usually follow a genuine change in circumstances.

Who created the IPIP-16PF, and is this the real version?

It was published by International Personality Item Pool (IPIP). IPIP items are explicitly public domain: "one can copy, edit, translate, or use them for any purpose without asking permission and without paying a fee." The items here are the published ones rather than a paraphrase, and the scoring follows the original rules. Both are documented on this page so they can be checked.

How accurate is the IPIP-16PF?

Screening questionnaires are good at flagging that something merits attention and poor at establishing what it is. This one is sensitive to how you feel on the day you take it, and many instruments were validated on narrow populations whose cut-offs may not transfer cleanly to everyone. The references at the foot of this page are the primary sources.