Indexes and scales

There are four index scores representing major components of intelligence:

    * Verbal Comprehension Index (VCI)
    * Perceptual Reasoning Index (PRI)
    * Working Memory Index (WMI)
    * Processing Speed Index (PSI)

Two broad scores are also generated, which can be used to summarize general intellectual abilities:

    * Full Scale IQ (FSIQ), based on the total combined performance of the VCI, PRI, WMI, and PSI
    * General Ability Index (GAI), based only on the six subtests that comprise the VCI and PRI