Comparison
IPIP-NEO and NEO PI-R: what is the difference?
They share a structure of five domains and thirty facets. They are separate inventories, with different items, different owners and different terms of use.
| IPIP-NEO | NEO PI-R | |
|---|---|---|
| Publisher | Public domain (IPIP) | Psychological Assessment Resources (PAR) |
| Cost to use the items | None | Commercial licence |
| Facets | 30, six per domain | 30, six per domain |
| Items | 300 or 120, written by Goldberg and Johnson | 240, written by Costa and McCrae |
| Name | IPIP-NEO | “NEO” and “NEO PI-R” are PAR trademarks |
What they share
The IPIP-NEO was written to measure the thirty facets that the NEO PI-R defined, so the two have the same layout. Six facets sit inside each of the five domains, and most facets have a direct counterpart, listed below under a different name in some cases.
| Domain | IPIP-NEO facet | Parallel facet in the NEO PI-R |
|---|---|---|
| Neuroticism | Anxiety | Anxiety |
| Neuroticism | Anger | Angry Hostility |
| Neuroticism | Depression | Depression |
| Neuroticism | Self-Consciousness | Self-Consciousness |
| Neuroticism | Immoderation | Impulsiveness |
| Neuroticism | Vulnerability | Vulnerability |
| Extraversion | Friendliness | Warmth |
| Extraversion | Gregariousness | Gregariousness |
| Extraversion | Assertiveness | Assertiveness |
| Extraversion | Activity Level | Activity |
| Extraversion | Excitement-Seeking | Excitement-Seeking |
| Extraversion | Cheerfulness | Positive Emotions |
| Openness | Imagination | Fantasy |
| Openness | Artistic Interests | Aesthetics |
| Openness | Emotionality | Feelings |
| Openness | Adventurousness | Actions |
| Openness | Intellect | Ideas |
| Openness | Liberalism | Values |
| Agreeableness | Trust | Trust |
| Agreeableness | Morality | Straightforwardness |
| Agreeableness | Altruism | Altruism |
| Agreeableness | Cooperation | Compliance |
| Agreeableness | Modesty | Modesty |
| Agreeableness | Sympathy | Tender-Mindedness |
| Conscientiousness | Self-Efficacy | Competence |
| Conscientiousness | Orderliness | Order |
| Conscientiousness | Dutifulness | Dutifulness |
| Conscientiousness | Achievement-Striving | Achievement Striving |
| Conscientiousness | Self-Discipline | Self-Discipline |
| Conscientiousness | Cautiousness | Deliberation |
What differs
The NEO PI-R is a commercial inventory published by Psychological Assessment Resources, which holds the trademark on the name and the copyright on its items. The IPIP-NEO items were written independently and released into the public domain, so they can be used, translated and adapted without a licence. Different items mean a different instrument: a score from one is not a score from the other.
In practice
- Compare IPIP-NEO scores with norms built on the IPIP-NEO, and NEO PI-R scores with NEO PI-R norms.
- Where a paper reports NEO PI-R results, treat IPIP-NEO findings as relating to the same constructs, not as the same measurements.
- How closely a particular IPIP-NEO scale tracks its NEO PI-R counterpart is a question for the validation studies; Goldberg (1999) and Johnson (2014) are where to look.