Focus on how people use their intelligence not how much they have. Contextual Subtheory - deals with ability to use intelligence to solve problems. How they organize problems in a meaningful way. Experiential Subtheory - how a person masters handling of novel tasks in an automatic manner. Includes ordering and monitoring performance.
Intelligence involves all three subtheories.
Binet coined concept of mental age - age the child is functioning cognitively. The no. of points a score vaires because of error in measurement. SEM of 3 with a score of 115 indicates score is between 112-118. Validity - does the test measure what it proports to measure. Critique of Test Validity 1.