Methodology & Sources
We publish exactly which instrument powers each test, so you can judge the science yourself instead of taking our word for it.
Big Five Personality Test
This test is the IPIP-NEO-120, developed by Dr. John A. Johnson (2014) from the International Personality Item Pool (IPIP).
The IPIP is a public-domain project started by Dr. Lewis Goldberg (1999) so researchers could use validated personality items without licensing fees.
In Johnson's largest validation sample (619,150 people), the five broad scales reported internal-consistency alphas of .90 (Neuroticism), .89 (Extraversion), .81 (Openness), .86 (Agreeableness), and .90 (Conscientiousness). The 30 individual facet scales averaged lower, from .63 to .88.
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.
Goldberg, L. R. (1999). A broad-bandwidth, public domain, personality inventory measuring the lower-level facets of several five-factor models. Personality Psychology in Europe, 7, 7-28.
Career Test
This test uses the O*NET Interest Profiler Short Form, 60 items built on Holland's RIASEC model and published by the U.S. Department of Labor's Employment and Training Administration.
Occupation data (salary, outlook, education, tasks) comes from the O*NET Database, used here under its CC BY 4.0 license with attribution.
Across a sample of 1,061 people, internal-consistency alphas for the six RIASEC scales ranged from .78 to .87 (average .81). Three-to-four-week test-retest correlations ranged from .78 to .86 (average .82).
Rounds, J., Su, R., Lewis, P., & Rivkin, D. (2010). O*NET Interest Profiler Short Form Psychometric Characteristics: Summary. National Center for O*NET Development.
Trait Quizzes
Six shorter tests on this site each measure one trait with a single public-domain scale from the International Personality Item Pool. Every one uses IPIP's own item wording, not a copyrighted instrument's.
Assertiveness Test
This test uses the E3 Assertiveness facet from IPIP's public-domain representation of the NEO PI-R, the same item family behind our Big Five test. All 10 published items are used as-is.
Reported internal consistency for this facet is alpha = .84. Our 10-50 score range and its three bands (low/moderate/high) are our own choice, not an official IPIP cutoff.
International Personality Item Pool. NEO PI-R Facet Scales, E3 Assertiveness.
Emotional Intelligence Test
This test combines two of Kimberly Barchard's seven public-domain IPIP Emotional Intelligence sub-scales, Attending to Emotions and Responsive Joy, 20 items total.
Barchard reports internal consistency of alpha = .81/.83 (women/men) for Attending to Emotions and alpha = .73/.70 for Responsive Joy. Combining both into one score, and our score bands, are our own choice, not an official composite.
Barchard, K. A. (2001). Emotional and social intelligence: Examining its place in the nomological network. Unpublished doctoral dissertation, University of British Columbia.
Entrepreneurial Mindset Test
This test uses IPIP's Risk-Taking scale, a public-domain proxy for the Jackson Personality Inventory-Revised's "Opportunistic" cluster, 10 items.
Reported internal consistency is alpha = .78. This scale measures general risk tolerance and sensation-seeking, not business skill on its own; our score range and bands are our own choice.
International Personality Item Pool. JPI-R Preliminary Items Key, Risk-Taking.
Locus of Control Test
This test uses IPIP's Internality scale, a public-domain proxy for the Internality sub-scale of Levenson's Multidimensional Locus of Control, 10 items.
Reported internal consistency is alpha = .71. A higher score reflects a more internal locus of control; our score range and bands are our own choice, not an official Levenson cutoff.
Levenson, H. (1981). Differentiating among internality, powerful others, and chance. In H. M. Lefcourt (Ed.), Research with the Locus of Control Construct (Vol. 1, pp. 15-63). Academic Press.
Optimism Test
This test uses IPIP's Optimism scale, a public-domain proxy for Scheier, Carver, and Bridges' Life Orientation Test-Revised (LOT-R), 10 items.
Reported internal consistency is alpha = .86. We use IPIP's proxy wording rather than the LOT-R's own, since the LOT-R isn't confirmed free for commercial use; our score range and bands are our own choice.
Scheier, M. F., Carver, C. S., & Bridges, M. W. (1994). Distinguishing optimism from neuroticism (and trait anxiety, self-mastery, and self-esteem): A reevaluation of the Life Orientation Test. Journal of Personality and Social Psychology, 67(6), 1063-1078.
Self-Esteem Test
This test uses IPIP's Self-Esteem scale, a public-domain item set built to measure the same construct as Rosenberg's Self-Esteem Scale, though it doesn't reuse Rosenberg's original wording.
Reported internal consistency is alpha = .84. We use IPIP's own item set since the original Rosenberg wording's commercial-use license isn't clearly confirmed; our score range and bands are our own choice.
Rosenberg, M. (1965). Society and the Adolescent Self-Image. Princeton University Press. IPIP item set.
Original Instruments
The Enneagram and 16 Types tests on this site are our own original questionnaires, written for entertainment and self-reflection rather than adapted from a licensed clinical instrument. Because we wrote them ourselves, no peer-reviewed reliability or validity study exists for either one yet; we say so plainly instead of citing a number that doesn't exist. We label both clearly wherever they appear.
What We Don't Do
None of our tests are clinical or diagnostic tools. They don't screen for, diagnose, or treat any mental health condition, including ADHD, depression, anxiety, or personality disorders.
Our 16 Types test is not MBTI, Myers-Briggs, or any other trademarked instrument, and our Enneagram test is not the RHETI. Results here are for self-reflection only and don't substitute for an assessment by a licensed professional.
How Scoring Works
Every test runs entirely in your browser. Answers are scored with open-source, published scoring logic, nothing is sent to a server, and nothing is stored.
Common Questions
Is any test on this site a diagnostic tool?
No. Every test here is for education and self-reflection. None of them diagnose a mental health condition, and none replace an assessment by a licensed professional.
Is your 16 Types test the same as MBTI?
No. It's an original questionnaire we wrote, informed by the public Jungian dichotomies (Introversion/Extraversion, Sensing/Intuition, Thinking/Feeling, Judging/Perceiving) but using none of MBTI's copyrighted items or scoring. We're not affiliated with The Myers & Briggs Foundation or The Myers-Briggs Company.
Why don't the Enneagram and 16 Types sections cite a reliability score?
Because none exists. Both are original instruments we wrote ourselves, not adaptations of a published, peer-reviewed scale, so there's no reliability or validity coefficient we can honestly cite.
Where can I read the original sources myself?
Every citation on this page links to its primary source: the IPIP website (ipip.ori.org) for the personality items, and the O*NET Resource Center (onetcenter.org) for the career interest and occupation data.