Methodology
How these reviews are made
The rules this site holds itself to, the criteria behind every evidence grade, and an honest account of what an earlier version of this site published that it should not have.
What we promise
Every number carries a source
Reliability coefficients, validity estimates, item counts, and prices are attributed to a specific publication, technical manual, or the publisher’s own current pricing page. Where a figure varies by version or sample, the range is given rather than a single flattering number.
No invented authors and no invented research
This site publishes no bylines for people who do not exist and no original studies it has not run. Reviews are written and maintained by the Personality Metrics editorial team and stand on the cited literature, not on borrowed credentials.
Popularity is reported separately from evidence
An assessment can be enjoyable, widely used, and weakly supported all at once. Each review scores evidence quality and practical usefulness on separate scales so a fun instrument is never dressed up as a validated one.
Independence from publishers
Personality Metrics sells no assessments, takes no publisher sponsorship, and has no affiliate arrangement with any instrument reviewed here. The site is funded by advertising, which has no influence on ratings.
Nothing here is a diagnosis
These are self-report instruments for reflection and, at best, structured conversation. None of them can diagnose a psychological condition, and no result on this site should be used to make a clinical or hiring decision.
What each evidence grade requires
Grades describe the state of the research, not how much we enjoyed the instrument. Usefulness is a separate score for exactly that reason.
Independent peer-reviewed replication of both reliability and construct validity, by researchers with no commercial stake in the instrument. A publisher’s own technical manual never suffices on its own.
Serious psychometric documentation exists and the construct is recognisable in the established literature, but the evidence is largely vendor-published or the independent replication is thin.
CliftonStrengths, DiSC, Emotional Intelligence, YouScience Discovery
Some peer-reviewed work exists and it is mixed, preliminary, or contradicts a central claim the instrument makes about itself.
No published psychometric validation of the instrument, or a premise contradicted by better-established research.
Who writes this
Reviews are written and maintained by the Personality Metrics editorial team. We do not publish individual bylines, and that is a deliberate choice rather than an oversight: an earlier version of this site attached reviews to named psychologists with doctorates and university affiliations who did not exist, and the correct fix is not to invent better-documented people. It is to let the reviews stand on the literature they cite.
Every empirical claim in the assessment database is stored as a structured record that cannot be saved without a source attached. That is enforced in the type system rather than by editorial discipline, because editorial discipline is what failed last time. The site currently cites 38 distinct sources across 13 reviews.
Facts are re-checked at least every 12 months, and every review page shows the date its facts were last verified. Prices in particular move, and a price we checked in August 2026 may not be the price you see.
What this site got wrong
A correction, published rather than quietly deleted
Before this rebuild, Personality Metrics published fabricated content. Specifically: reviews bylined to invented experts including a clinical psychologist with a claimed Stanford doctorate; quotes attributed to invented researchers at named real institutions; an original research study that was never conducted, reporting a survey of 1,247 users and an analysis of over 50,000 test results; and a series of invented statistics presented as findings, including an “87 percent accuracy” figure for the Big Five predicting work performance that corresponds to nothing in the literature.
None of that was true. All of it has been removed, the site now cites real sources for every figure, and the structure that allowed unsourced numbers to be written in prose has been replaced with one that will not accept a claim without a citation. This note stays on the page because a site that asks you to judge instruments by their evidence should be willing to be judged the same way.
Common claims we no longer repeat
- That emotional intelligence “accounts for 58 percent of performance” or that “90 percent of top performers have high EQ”. Both are vendor marketing and appear in no peer-reviewed journal. The meta-analytic correlations with job performance are roughly .20 for ability measures and .29 for mixed measures.
- That the Enneagram is an ancient system. The nine-type personality framework was developed by Oscar Ichazo from the 1950s and elaborated by Claudio Naranjo in the 1970s.
- That 16Personalities is a Myers-Briggs product, or a hybrid of MBTI and the Big Five. Its publisher states it deliberately did not incorporate Jungian cognitive functions and rebuilt on trait dimensions instead.
- That aptitude testing eliminates socioeconomic bias. No assessment does, and cognitive and aptitude measures are among the best-documented for showing socioeconomically patterned differences.
- That “65 percent of students will work in jobs that do not exist yet”. This figure has no traceable source and the report it is usually attributed to says close to the opposite.
Every source cited on this site
Assembled automatically from the assessment database, so this list cannot fall out of step with the reviews.
- Everything DiSC Research Report, John Wiley & Sons
technical manual Cited in: DiSC
- YouScience Discovery (publisher materials)
publisher Cited in: YouScience Discovery
- NERIS Analytics, 16Personalities (publisher materials)
publisher Cited in: 16Personalities
- Herrmann Global (publisher materials)
publisher Cited in: HBDI
- Rubin, The Four Tendencies quiz (publisher materials)
publisher Cited in: The Four Tendencies
- True Colors International (publisher materials)
publisher Cited in: Colour Personality Systems
- Sackett, Zhang, Berry & Lievens (2022), Journal of Applied Psychology, 107(11), 2040-2068
peer reviewed Cited in: The Big Five
- Hook, Hall, Davis, Van Tongeren & Conner (2021), Journal of Clinical Psychology, 77(4), 865-883
peer reviewed Cited in: Enneagram
- Kirk, MacDonald, Lavender, Dean & Rubin (2021), applying the Four Tendencies to treatment adherence
peer reviewed Cited in: The Four Tendencies
- Makwana & Dave (2020), International Journal of Management, 11(9), 257-265
peer reviewed Cited in: 16Personalities
- Soto (2019), Psychological Science, 30(5), 711-727
peer reviewed Cited in: The Big Five
- Ghielen, van Woerkom & Christina Meyers (2018), Journal of Positive Psychology, 13(6), 573-585
meta analysis Cited in: CliftonStrengths
- Soto & John (2017), Journal of Personality and Social Psychology, 113(1), 117-143
peer reviewed Cited in: BFI-2
- Soto & John (2017), Journal of Research in Personality, 68, 69-81
peer reviewed Cited in: BFI-2
- Johnson (2014), Journal of Research in Personality, 51, 78-89
peer reviewed Cited in: The Big Five
- Nielsen, Zielinski, Ferguson, Lainhart & Anderson (2013), PLoS ONE, 8(8), e71275
peer reviewed Cited in: HBDI
- O’Boyle, Humphrey, Pollack, Hawver & Story (2011), Journal of Organizational Behavior, 32(5), 788-818
meta analysis Cited in: Emotional Intelligence
- Joseph & Newman (2010), Journal of Applied Psychology, 95(1), 54-78
meta analysis Cited in: Emotional Intelligence
- Ashton & Lee (2009), Journal of Personality Assessment, 91(4), 340-345
peer reviewed Cited in: HEXACO
- Pashler, McDaniel, Rohrer & Bjork (2008), Psychological Science in the Public Interest, 9(3), 105-119
review body Cited in: HBDI
- Roberts, Kuncel, Shiner, Caspi & Goldberg (2007), Perspectives on Psychological Science, 2(4), 313-345
meta analysis Cited in: BFI-2, The Big Five, 16Personalities
- Asplund, Lopez, Hodges & Harter, The Clifton StrengthsFinder 2.0 Technical Report, Gallup
technical manual Cited in: CliftonStrengths
- Lee & Ashton (2005), Personality and Individual Differences, 38(7), 1571-1582
peer reviewed Cited in: HEXACO
- Pittenger (2005), Consulting Psychology Journal: Practice and Research, 57(3), 210-221
peer reviewed Cited in: 16Personalities, MBTI, Colour Personality Systems
- Lee & Ashton (2004), Multivariate Behavioral Research, 39(2), 329-358
peer reviewed Cited in: HEXACO
- Ashton, Lee, Perugini, Szarota, de Vries, Di Blas, Boies & De Raad (2004), Journal of Personality and Social Psychology, 86(2), 356-366
peer reviewed Cited in: HEXACO
- Newgent, Parr, Newman & Higgins (2004), Measurement and Evaluation in Counseling and Development, 36(4), 226-237
peer reviewed Cited in: Enneagram
- Roberts & DelVecchio (2000), Psychological Bulletin, 126(1), 3-25
meta analysis Cited in: The Big Five
- Deci & Ryan (2000), Psychological Inquiry, 11(4), 227-268
peer reviewed Cited in: The Four Tendencies
- Goldberg (1999), Personality Psychology in Europe, 7, 7-28; IPIP validity documentation
peer reviewed Cited in: The Big Five
- Schmidt & Hunter (1998), Psychological Bulletin, 124(2), 262-274
meta analysis Cited in: YouScience Discovery
- Hartman, The Color Code (Scribner, 1998), p. 40
publisher Cited in: Colour Personality Systems
- Baron (1996), Journal of Occupational and Organizational Psychology, 69(1), 49-56
peer reviewed Cited in: CliftonStrengths
- Barrick & Mount (1991), Personnel Psychology, 44(1), 1-26; 117 studies, 162 samples, N = 23,994
meta analysis Cited in: The Big Five
- Druckman & Bjork (eds.), In the Mind’s Eye: Enhancing Human Performance, National Research Council
review body Cited in: MBTI
- McCrae & Costa (1989), Journal of Personality, 57(1), 17-40
peer reviewed Cited in: MBTI
- Wiggins (1979), Journal of Personality and Social Psychology, 37(3), 395-412
peer reviewed Cited in: DiSC
- Marston, Emotions of Normal People, Kegan Paul
peer reviewed Cited in: DiSC
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