Knowledge Hub

33 indexable URLs · XML: /sitemaps/sitemap-knowledge.xml

• Cattell Culture Fair III

  https://certifiediq.org/entity/cattell-culture-fair/

  Culture-reduced non-verbal reasoning test associated with fluid intelligence measurement.

  Last updated: 2026-07-27

• Charles Spearman

  https://certifiediq.org/experts/charles-spearman/

  Last updated: 2026-07-27

• Cognitive domains

  https://certifiediq.org/glossary/cognitive-domains/

  Cognitive domains are distinct areas of mental ability such as reasoning, memory, processing speed, and verbal comprehension.

  Last updated: 2026-07-27

• Crystallized intelligence

  https://certifiediq.org/glossary/crystallized-intelligence/

  Crystallized intelligence (Gc) is accumulated knowledge, vocabulary, and learned skills applied in familiar contexts.

  Last updated: 2026-07-27

• David Wechsler

  https://certifiediq.org/experts/david-wechsler/

  Last updated: 2026-07-27

• Experts index

  https://certifiediq.org/experts/

  Editorial and science team profiles.

  Last updated: 2026-07-27

• Fluid intelligence

  https://certifiediq.org/glossary/fluid-intelligence/

  Fluid intelligence (Gf) is the capacity to solve novel problems and detect patterns without relying on stored knowledge.

  Last updated: 2026-07-27

• General Intelligence (1904)

  https://certifiediq.org/references/spearman-1904-general-intelligence/

  Spearman reported positive correlations among diverse mental tests and argued for a general factor (g) underlying performance, alongside task-specific factors.

  Last updated: 2026-07-27

• Glossary index

  https://certifiediq.org/glossary/

  Psychometric terminology and definitions.

  Last updated: 2026-07-27

• IQ percentile calculator

  https://certifiediq.org/tools/iq-percentile-calculator/

  Convert IQ scores to percentiles using the normal distribution.

  Last updated: 2026-07-27

• IQ score

  https://certifiediq.org/glossary/iq-score/

  An IQ score is a standardized index of cognitive performance relative to a norm group, typically scaled to mean 100.

  Last updated: 2026-07-27

• John C. Raven

  https://certifiediq.org/experts/john-raven/

  Last updated: 2026-07-27

• Mensa

  https://certifiediq.org/glossary/mensa/

  Mensa is a high-IQ society that accepts members who score at or above the 98th percentile on approved supervised tests.

  Last updated: 2026-07-27

• Mensa International

  https://certifiediq.org/entity/mensa/

  Largest high-IQ society; membership requires scores at or above the 98th percentile on approved supervised tests.

  Last updated: 2026-07-27

• Norms

  https://certifiediq.org/glossary/norms/

  Norms are reference data from representative samples used to interpret raw scores as percentiles or standard scores.

  Last updated: 2026-07-27

• Percentile

  https://certifiediq.org/glossary/percentile/

  A percentile ranks your score against a reference population — e.g., the 90th percentile means you scored higher than about 90% of the norm group.

  Last updated: 2026-07-27

• Raven's Progressive Matrices

  https://certifiediq.org/glossary/raven-progressive-matrices/

  Raven's Progressive Matrices (RPM) are non-verbal visual puzzles used to estimate fluid reasoning ability.

  Last updated: 2026-07-27

• Raven's Progressive Matrices

  https://certifiediq.org/entity/raven-progressive-matrices/

  Non-verbal matrix puzzles designed to estimate fluid reasoning (Gf) with minimal language load.

  Last updated: 2026-07-27

• Raymond B. Cattell

  https://certifiediq.org/experts/raymond-cattell/

  Last updated: 2026-07-27

• Refinement of Fluid and Crystallized Intelligence (1966)

  https://certifiediq.org/references/horn-cattell-1966-refinement/

  Horn and Cattell refined the Gf-Gc theory with additional factor-analytic evidence, strengthening the distinction between fluid and crystallized broad abilities.

  Last updated: 2026-07-27

• Reliability

  https://certifiediq.org/glossary/reliability/

  Reliability is the consistency of measurement — whether repeated testing yields similar results.

  Last updated: 2026-07-27

• Scientific references

  https://certifiediq.org/references/

  Curated research references for IQ psychometrics.

  Last updated: 2026-07-27

• Standard deviation

  https://certifiediq.org/glossary/standard-deviation/

  Standard deviation (SD) measures score spread around the mean; IQ tests commonly use SD 15 (Wechsler) or SD 16 (Stanford-Binet).

  Last updated: 2026-07-27

• Stanford-Binet

  https://certifiediq.org/glossary/stanford-binet/

  The Stanford-Binet Intelligence Scales are a major individually administered IQ battery spanning ages 2 to 85+.

  Last updated: 2026-07-27

• Stanford-Binet Intelligence Scales

  https://certifiediq.org/entity/stanford-binet/

  Historic and modern individual IQ battery covering ages 2 through adulthood (SB5).

  Last updated: 2026-07-27

• Theory of Fluid and Crystallized Intelligence (1963)

  https://certifiediq.org/references/cattell-1963-fluid-crystallized/

  Cattell proposed that intelligence comprises fluid ability (novel problem solving) and crystallized ability (accumulated knowledge), a framework widely used in test manuals.

  Last updated: 2026-07-27

• Topics index

  https://certifiediq.org/topics/

  Pillar topic clusters for IQ and cognitive assessment.

  Last updated: 2026-07-27

• Validity

  https://certifiediq.org/glossary/validity/

  Validity is the degree to which a test measures what it claims to measure.

  Last updated: 2026-07-27

• WAIS

  https://certifiediq.org/glossary/wais/

  The Wechsler Adult Intelligence Scale (WAIS) is a leading individually administered IQ battery for adults.

  Last updated: 2026-07-27

• Wechsler Adult Intelligence Scale (WAIS)

  https://certifiediq.org/entity/wais/

  Gold-standard individually administered adult intelligence battery published by Pearson.

  Last updated: 2026-07-27

• Wechsler Intelligence Scale for Children (WISC)

  https://certifiediq.org/entity/wisc/

  Leading individually administered intelligence battery for school-age children.

  Last updated: 2026-07-27

• Working memory

  https://certifiediq.org/glossary/working-memory/

  Working memory is the ability to hold and manipulate information briefly while performing a task.

  Last updated: 2026-07-27

• g factor

  https://certifiediq.org/glossary/g-factor/

  The general intelligence factor (g) is a statistical construct representing shared variance across diverse cognitive tasks.

  Last updated: 2026-07-27