Personality terms, without the jargon

Concepts & measurement

Trait

A stable tendency to feel, think and act a certain way, relatively constant across time and situations, as opposed to a passing state. See in Big Five →

State

A momentary psychological condition (feeling anxious today) that varies with context. Unlike a trait, which is the lasting tendency.

Facet

A more specific subcomponent of a broad trait. E.g., within Extraversion, facets like assertiveness and excitement-seeking.

Construct

An abstract concept a test tries to measure (extraversion, self-esteem). It is never observed directly, only inferred from answers.

Domain

Each broad dimension of a model. In the Big Five the five domains are openness, conscientiousness, extraversion, agreeableness and emotional stability.

Self-report

A method where the person answers about themselves. Practical and informative, but subject to limited self-perception and biases. See the methodology →

Likert scale

A graded response format (from “strongly disagree” to “strongly agree”) that measures intensity instead of yes/no. Devised by Rensis Likert (1932).

Item

Each statement or question in a test. Several items summed estimate a construct more stably than any single one.

Test-retest reliability

How similar a test's results are when the same person retakes it at different times. Low reliability means the label can change without the person having changed.

Internal consistency (Cronbach's alpha)

How much the items measuring the same construct agree with each other. “Alpha” (α) sums this in a 0–1 number; above 0.70 is usually acceptable.

Validity

How well a test actually measures what it claims to — and predicts what it should.

Percentile

Your standing relative to a reference group. The 70th percentile means scoring above 70% of that sample, not “70% of a trait”.

Normative sample

The reference group your result is compared against. Whether a score reads high or low depends on who that sample is.

Social desirability bias

The tendency to answer in a socially acceptable rather than fully honest way, one of the main distortions in self-report.

Acquiescence

The tendency to agree with statements regardless of content. Good tests mix “direct” and “reverse” items to control for it.

Type vs. dimension

A type sorts you into closed categories (you're A or B); a dimension measures intensity on a continuum. Most traits are dimensional, not categorical. See in 16 types →

Self-knowledge

The process of observing and understanding your own patterns of thought, emotion and behavior — the purpose of every test on this site.

Models, theories & tests

Five-Factor Model (Big Five / OCEAN)

The most established model in personality psychology, built on five dimensions: Openness, Conscientiousness, Extraversion, Agreeableness and Emotional stability (the OCEAN acronym). It emerged from the analysis of language, the lexical hypothesis. Take the test →

HEXACO

A six-factor model adding an Honesty-Humility dimension to the Big Five. Proposed by Ashton and Lee.

DISC

A model of behavioral styles in four dimensions: Dominance, Influence, Steadiness and Caution. It comes from William Moulton Marston's work (1928), now in the public domain. Take the test →

Enneagram

A system of nine types centered on core motivations and fears. Popular and useful for reflection, though the empirical support is weak; read it as a mirror rather than a verdict. Take the test →

RIASEC (Holland code)

A model of career interests in six areas arranged in a hexagon: Realistic, Investigative, Artistic, Social, Enterprising and Conventional. Basis of the O*NET Interest Profiler. Take the test →

Theory of Basic Values (Schwartz)

A map of ten basic human values (e.g., self-direction, security, benevolence) arranged in a circle where opposite values conflict. Proposed by Shalom Schwartz (1992). Take the test →

Self-Determination Theory (SDT)

Deci and Ryan's theory of motivation centered on three basic psychological needs: autonomy, competence and relatedness. See in Drivers →

Drivers (Pink)

Daniel Pink's (2009) popularization of SDT into three engines of intrinsic motivation: autonomy, mastery and purpose. Take the test →

Emotional Intelligence

The ability to perceive, understand, use and regulate emotions — your own and others'. A construct formulated by Salovey and Mayer (1990) and popularized by Daniel Goleman (1995). Take the test →

Psychological types (Jung)

The theoretical basis of 16-type systems: Carl Jung's (1921) dichotomies, like introversion–extraversion. They inspire several tests without being any one brand. See in 16 types →

Self-esteem (Rosenberg scale)

A classic 10-item scale measuring the overall positive or negative attitude toward oneself. Created by Morris Rosenberg (1965), in the public domain.

Scientists & authors

Gordon Allport

American psychologist, pioneer of trait theory; with Odbert (1936) catalogued thousands of personality terms in language (the lexical hypothesis).

Raymond Cattell

Psychologist who reduced traits to 16 factors (the 16PF), one of the forerunners of the Big Five.

Lewis Goldberg

Psychologist who consolidated the term “Big Five” and created the IPIP, the open item bank used on this site.

Paul Costa and Robert McCrae

Authors of the Five-Factor Model (FFM) and the NEO inventory, which detailed the five domains into facets.

Oliver John

Big Five researcher and author of the Big Five Inventory (BFI), widely used in research.

William Moulton Marston

Psychologist, author of Emotions of Normal People (1928), the work behind the four-style DISC model.

John Holland

Vocational psychologist who created the RIASEC model of career interests and the Holland hexagon.

Shalom Schwartz

Social psychologist, author of the theory of basic human values, validated across dozens of countries.

Edward Deci and Richard Ryan

Creators of Self-Determination Theory (1985), a reference on intrinsic and extrinsic motivation.

Daniel Pink

Author of Drive (2009), which popularized autonomy, mastery and purpose as engines of motivation.

Morris Rosenberg

Sociologist, author of the Rosenberg Self-Esteem Scale (1965), one of the most used in the world.

Peter Salovey and John Mayer

Psychologists who formulated the construct of emotional intelligence (1990) as a set of abilities.

Daniel Goleman

Psychologist and journalist who popularized emotional intelligence with his 1995 book.

Carl Gustav Jung

Swiss psychiatrist, author of Psychological Types (1921); his dichotomies inspired 16-type systems.

Sources, bodies & acronyms

IPIP

International Personality Item Pool — a public, free bank of personality items (founded by Lewis Goldberg), the source of several items on this site.

O*NET

An occupations database maintained by the U.S. Department of Labor; includes the Interest Profiler, basis of RIASEC.

APA

American Psychological Association, the largest psychology body in the U.S. and a reference for test standards and ethics.

SATEPSI

The Psychological Test Assessment System of Brazil's Federal Council of Psychology, which approves which tests may be used professionally.

CFP

Conselho Federal de Psicologia, the body that regulates the profession in Brazil and maintains SATEPSI.

CRP

Conselho Regional de Psicologia, where a psychologist registers. Only professionals with a CRP administer recognized tests.

OCEAN

Acronym for the five factors: Openness, Conscientiousness, Extraversion, Agreeableness, Neuroticism.

FFM

Five-Factor Model, another name for the Big Five. It is associated with the NEO inventory of Costa and McCrae.

NEO-PI-R

Costa and McCrae's revised NEO-PI, an inventory measuring the five factors and the six facets of each. Proprietary; we use equivalent open items from IPIP.

BFI

Big Five Inventory, Oliver John's 44-item questionnaire measuring the five factors; widely used in research.

16PF

Sixteen Personality Factor Questionnaire, by Raymond Cattell — a forerunner of the Big Five, measuring 16 primary traits.

SDT

Self-Determination Theory, the framework behind the Drivers test.

EQ

Emotional Quotient, a popular term for emotional intelligence. Useful as a metaphor, though not an exact measure.

Public domain

Works and scales whose rights have expired or been released (e.g., Marston 1928, Rosenberg 1965), free to use and adapt.

MBTI®

A commercial 16-type instrument and registered trademark. We don't use it or its type names; this site has its own models and names.

By Vinicius Fonseca · Original definitions, anchored in open sources · Updated July 2026 · Methodology