The Five-Factor Model and the IPIP-NEO-120
The Five-Factor Model describes personality through five broad traits, each with six more specific facets, thirty in all. The IPIP-NEO-120 measures both through 120 questions. Developed by John A. Johnson in 2014, it draws on a public dataset of more than 600,000 responses. Your results help explain how you make decisions, work with others, and respond to pressure.
About this note
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Understand what your personality results mean at work.
At a glance
Five broad personality traits, with six facets within each. The IPIP-NEO-120 is a 120-item public-domain measure of them, with an open dataset of more than 600,000 respondents. It is a development tool, not a hiring test. Your results offer a starting point for understanding how you make decisions, work with others, and respond to pressure.
Research reviewed: Johnson's 2014 study and the published reference dataset.
- 600k+
- responses in the research dataset, including the 243,171 US responses used for these percentiles.
- 5
- broad personality traits, with thirty facets.
The five personality dimensions
The Five-Factor Model grew out of decades of research into patterns in personality. By the early 1990s, five broad dimensions had become a widely accepted framework. Researchers studied how people describe one another and how answers to thousands of personality questions grouped together. Both approaches supported the same five broad dimensions. Lewis Goldberg, who coined the term, called them the Big Five. Costa and McCrae developed the same structure in parallel as the Five-Factor Model. Many commercial personality assessments used in leadership development draw on this framework.
Each trait is measured on a spectrum. Most people fall between the extremes. A trait that helps in one situation may call for a different approach in another. The model helps you put words to how you work with others, make decisions, and handle different situations.
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How the IPIP-NEO-120 was developed
The IPIP-NEO-120 measures these traits through 120 questions. Its questions come from the International Personality Item Pool, a public collection of questions used in personality research. Dr. John A. Johnson assembled and validated the 120-item version. It measures all five domains and six facets within each, for thirty facet scales in total. His development paper was published in the Journal of Research in Personality in 2014.
The IPIP-NEO-120 makes its questions and methods publicly available. The items are openly licensed and free for any use, including commercial, with no permission or fee required. Anyone can review the questions, scoring methods, and research behind the assessment. The IPIP-NEO-120 measures the same five broad personality domains used by many commercial assessments, with publicly available methods.
What your percentile means
Your percentile shows how your score compares with a reference group. A percentile of 70 means you scored higher than roughly seven in ten people in that sample. The IPIP-NEO-120 percentiles used here are referenced to the US subset of Johnson’s public-domain dataset. The reference group includes 243,171 complete online responses from adults aged 18 to 75.
The reference group consists of people who voluntarily completed the assessment online, rather than a nationally representative sample. Your percentile compares your score with this group, whose results may differ from those of the wider US population.
Turn your results into development goals
Your Big Five profile can help you recognize your habits, build on your strengths, and identify development opportunities. Hiring assessments require separate evidence that they are appropriate for the selection decision.
Think about a recent decision, difficult conversation, or deadline. Which parts of your profile showed up? Where did your natural approach help, and what might you try differently? Bring those observations into your next coaching or development conversation.
Research and sources
Six research sources, most recently checked 29 June 2026.
- Johnson, J. A. (2014). Measuring thirty facets of the Five-Factor Model with a 120-item public domain inventory: Development of the IPIP-NEO-120. Journal of Research in Personality, 51, 78-89. The development and validation paper for the 120-item instrument, including its facet structure and the internet samples it was built on. doi.org
- International Personality Item Pool (ipip.ori.org). The public-domain source of the items, maintained as a scientific resource, openly licensed and free for any use including commercial. ipip.ori.org
- Johnson, J. A. IPIP-NEO-120 normative data repository (Open Science Framework). The public-domain dataset of more than 600,000 responses. The reference means, standard deviations, and percentiles used here come from its US subset of 243,171 complete responses aged 18 to 75. That includes the documentation that the sample is self-selected online respondents. osf.io
- Goldberg, L. R. (1993). The structure of phenotypic personality traits. American Psychologist, 48(1), 26-34. A foundational statement of the Big Five structure and the convergence of decades of trait research onto five dimensions. doi.org
- Barrick, M. R., and Mount, M. K. (1991). The Big Five personality dimensions and job performance: A meta-analysis. Personnel Psychology, 44(1), 1-26. This widely cited meta-analysis identifies Conscientiousness as the most consistent personality predictor of job performance across occupations. doi.org
- Soto, C. J., and John, O. P. (2017). The next Big Five Inventory (BFI-2). Journal of Personality and Social Psychology, 113(1), 117-143. Examines the five-domain, multiple-facet structure also used by the IPIP-NEO-120. doi.org
Common questions
What research supports the Big Five?
Researchers have studied the Five-Factor Model for decades across languages and cultures. That research supports its five broad dimensions, which also appear in many leadership development assessments.
What is the IPIP-NEO-120?
It is a 120-item public-domain measure of the Five-Factor Model, developed and validated by Dr. John A. Johnson and published in 2014. It scores all five domains plus thirty facets and draws its items from the International Personality Item Pool. Its questions and methods are publicly available for review and use.
Who am I being compared with?
To the US reference sample of Johnson’s public-domain dataset: 243,171 adults who completed the IPIP-NEO-120 online. That sample is self-selected rather than nationally representative. Its averages may differ from those of the wider US population. Your percentile shows where your score falls among people in the online reference group.
Can I use a personality profile to make hiring decisions?
A development-focused Big Five profile is built for self-understanding and growth, not for selection. Employers should use a separately validated selection assessment when making hiring decisions. Personality results describe tendencies and can support coaching and development.
Tools for the next step
Answer 120 questions in about 12 minutes and see percentiles for all five domains and thirty facets. Your result appears immediately, with no sign-up.
FreeA personalized workbook based on your Work Style Profile. Includes a chapter for each personality domain, exercises tailored to your results, and a 90-day development plan.
$39Explore how your five personality domains shape your leadership, feedback, delegation, and response to pressure. Includes common leadership challenges associated with your results and practical conversation scripts.
$69Review your Work Style Profile with a senior HR practitioner in a $99 Results Debrief. Discuss what your results mean for your work and leave with clear development priorities.
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