The technique of diagnostics of children with mental retardation preschool age forward this error screen to 172. Scores from intelligence tests are estimates of intelligence. Unlike, for example, distance and mass, a concrete measure of intelligence cannot be achieved given the abstract nature of the concept of “intelligence”.
IQ scores are used for educational placement, assessment of intellectual disability, and evaluating job applicants. Even when students improve their scores on standardized tests, they do not always improve their cognitive abilities, such as memory, attention and speed. Historically, even before IQ tests were devised, there were attempts to classify people into intelligence categories by observing their behavior in daily life. The English statistician Francis Galton made the first attempt at creating a standardized test for rating a person’s intelligence. French psychologist Alfred Binet, together with Victor Henri and Théodore Simon had more success in 1905, when they published the Binet-Simon test, which focused on verbal abilities. Goddard published a translation of it in 1910. The many different kinds of IQ tests include a wide variety of item content.
Some test items are visual, while many are verbal. Test items vary from being based on abstract-reasoning problems to concentrating on arithmetic, vocabulary, or general knowledge. The British psychologist Charles Spearman in 1904 made the first formal factor analysis of correlations between the tests. Spearman’s argument proposing a general factor of human intelligence is still accepted in principle by many psychometricians.