Revised NEO Personality Inventory

The Revised NEO Personality Inventory (NEO PI-R) is a personality inventory that assesses an individual on five dimensions of personality. These are the same dimensions found in the Big Five personality traits. These traits are openness to experience, conscientiousness, extraversion (-introversion), agreeableness, and neuroticism. In addition, the NEO PI-R also reports on six subcategories of each Big Five personality trait (called facets).

Historically, development of the Revised NEO PI-R began in 1978 when Paul Costa and Robert McCrae published a personality inventory. The researchers later published three updated versions of their personality inventory in 1985, 1992, and 2005. These were called the NEO PI (Neuroticism, Extraversion, Openness Personality Inventory), NEO PI-R (or Revised NEO PI), and NEO PI-3, respectively. The revised inventories feature updated vocabulary that could be understood by adults of any education level, as well as children.

The inventories have both longer and shorter versions, with the full NEO PI-R consisting of 240 items and providing detailed facet scores. By contrast, the shorter NEO-FFI (NEO Five-Factor Inventory) comprised 60 items (12 per trait). The test was originally developed for use with adult men and women without overt psychopathology. It has also been found to be valid for use with children.

A table of the personality dimensions measured by the NEO PI-R, including facets, is as follows:

In the most recent publication, there are two forms for the NEO, self-report (form S) and observer-report (form R) versions. Both forms consist of 240 items (descriptions of behavior) answered on a five-point Likert scale. Finally, there is a 60-item inventory, the NEO FFI. There are paper and computer versions of both forms.

The manual reports that administration of the full version should take between 30 and 40 minutes. Costa and McCrae reported that an individual should not be evaluated if more than 40 items are missing. They also state that despite the fact that the assessment is "balanced" to control for the effects of acquiescence and nay-saying, that if more than 150 responses, or fewer than 50 responses, are "agree" or "strongly agree", the results should be interpreted with caution.

Scores can be reported to most test-takers on "Your NEO Summary", which provides a brief explanation of the assessment, and gives the individuals domain levels and a strengths-based description of three levels (high, medium, and low) in each domain. For example, low N reads "Secure, hardy, and generally relaxed even under stressful conditions," whereas high N reads "Sensitive, emotional, and prone to experience feelings that are upsetting." For profile interpretation, facet and domain scores are reported in T scores and are recorded visually as compared to the appropriate norming group.

The internal consistency of the NEO scales was assessed on 1,539 individuals. The internal consistency of the NEO PI-R was high, at: N = .92, E = .89, O = .87, A = .86, C = .90. The internal consistency of the facet scales ranged from .56 to .81. The internal consistency of the NEO PI-3 was consistent with that of the NEO PI-R, with α ranging from .89 to .93 for the five domains. Internal consistency coefficient from the facets, with each facet scale comprising fewer items than each of the Big Five scales, were necessarily smaller, ranging from .54 to .83.