The Wechsler Intelligence Scale for Children (WISC), developed by David Wechsler, is an intelligence test for children between the ages of 6 and 16 inclusive. The WISC generates an IQ score.
The test comprises ten core subtests and five supplemental ones. The supplemental subtests are used to accommodate children in certain rare cases, or to make up for spoiled results which may occur from interruptions or other circumstances. Testers are allowed no more than two substitutions in any FSIQ test, or no more than one per index. These subtests then generate a Full Scale score (FSIQ), Verbal IQ and Performance IQ as well as four composite scores known as indices: Verbal Comprehension (VCI), Perceptual Organizational (POI), Processing Speed (PSI) and Working Memory (WMI).
The WISC is one of a family of Wechsler intelligence scales. Subjects over 16 are tested with the Wechsler Adult Intelligence Scale (WAIS), and children ages three to seven years, three months are tested with the Wechsler Preschool and Primary Scale of Intelligence (WPPSI).
Each of the ten core subtests is given equal weighting towards full-scale IQ. There are three subtests for both VCI and PRI, thus they are given 30% weighting each; in addition, PSI and WMI are given weighting for their two subtests each.
The VCI's subtests are as follows:

• Vocabulary - straightforward questions over the meaning of words
• Similiaries - asking how two concepts are alike
• Comprehension - questions about social situations or common concepts
• Information (supplemental) - general knowledge questions