Openness to experience in the context of Normal distribution

General knowledge is information that has been accumulated over time through various media and sources. It excludes specialized learning that can only be obtained with extensive training and information confined to a single medium. General knowledge is an essential component of crystallized intelligence. It is strongly associated with general intelligence and with openness to experience.

Studies have found that people who are highly knowledgeable in a particular domain tend to be knowledgeable in many. General knowledge is thought to be supported by long-term semantic memory ability. General knowledge also supports schemata for textual understanding.

In psychology and psychometrics, the big five personality trait model or five-factor model (FFM)—sometimes called by the acronym OCEAN or CANOE—is a scientific model for measuring and describing human personality traits. The framework groups variation in personality into five separate factors, all measured on a continuous scale:

• openness (O) measures creativity, curiosity, and willingness to entertain new ideas.
• conscientiousness (C) measures self-control, diligence, and attention to detail.
• extraversion (E) measures boldness, energy, and social interactivity.
• agreeableness (A) measures kindness, helpfulness, and willingness to cooperate.
• neuroticism (N) measures depression, irritability, and moodiness.

The five-factor model was developed using empirical research into the language people used to describe themselves, which found patterns and relationships between the words people use to describe themselves. For example, because someone described as "hard-working" is more likely to be described as "prepared" and less likely to be described as "messy", all three traits are grouped under conscientiousness. Using dimensionality reduction techniques, psychologists showed that most (though not all) of the variance in human personality can be explained using only these five factors.

In psychology, a facet is a specific and unique aspect of a broader personality trait. Both the concept and the term "facet" were introduced by Paul Costa and Robert McCrae in the first edition of the NEO-Personality Inventory (NEO-PI) Manual. Facets were originally elaborated only for the neuroticism, openness to experience, and extraversion traits; Costa and McCrae introduced facet scales for the agreeableness and conscientiousness traits in the Revised NEO-PI (NEO PI-R). Each of the Big Five personality traits in the five factor model contains six facets, each of which is measured with a separate scale. The use of facets and facet scales has since expanded beyond the NEO PI-R, with alternative facet and domain structures derived from other models of personality. Examples include the HEXACO model of personality structure, psycholexical studies, circumplex models (e.g., Goldberg's Abridged Big-Five Dimensional Circumplex), the Multidimensional Personality Questionnaire (MPQ), and the California Psychological 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 alternative five factor model of personality is based on the claim that the structure of human personality traits is best explained by five broad factors called impulsive sensation seeking (ImpSS), neuroticism–anxiety (N-Anx), aggression–hostility (Agg-Host), sociability (Sy), and activity (Act). The model was developed by Marvin Zuckerman and colleagues as a rival to the well-known five factor model of personality traits and is based on the assumption that "basic" personality traits are those with a strong biological-evolutionary basis. One of the salient differences between these two models is that the alternative five model lacks any equivalent to the dimension called openness to experience in the five factor model.