IQ World has always developed aptitude and IQ tests based on the principles defined by Wechsler’s and Stanford-Binet tests. However, we are also influenced by any others who have dedicated their lives to cognitive research.
There are a variety of individually administered IQ tests in use in the English-speaking world. The most commonly used individual IQ test series is the Wechsler Adult Intelligence Scale for adults and the Wechsler Intelligence Scale for Children for school-age test-takers. Other commonly used individual IQ tests (some of which do not label their standard scores as "IQ" scores) include the current versions of the Stanford-Binet, Woodcock-Johnson Tests of Cognitive Abilities, the Kaufman Assessment Battery for Children, the Cognitive Assessment System, and the Differential Ability Scales.
IQ tests that measure intelligence also include:
1. Stanford–Binet Intelligence Scales.
2. Woodcock–Johnson Tests of Cognitive Abilities.
3. Raven's Progressive Matrices.
4. Wechsler Adult Intelligence Scale
5. Cattell Culture Fair III.
6. Reynolds Intellectual Assessment Scales.
7. Thurstone's Primary Mental Abilities.
8. Differential Ability Scales.
9. Kaufman Brief Intelligence Test.
10. Multidimensional Aptitude Battery II.
11. Das–Naglieri cognitive assessment system.
Psychometricians generally regard IQ tests as having high statistical reliability. A high reliability implies that – although test-takers may have varying scores when taking the same test on differing occasions, and although they may have varying scores when taking different IQ tests at the same age – the scores generally agree with one another and across time. Like all statistical quantities, any particular estimate of IQ has an associated standard error that measures uncertainty about the estimate. For modern tests, the standard error of measurement is about three points. Clinical psychologists generally regard IQ scores as having sufficient statistical validity for many clinical purposes.
IQ scores can differ to some degree for the same person on different IQ tests, so a person does not always belong to the same IQ score range each time the person is tested.