WISC-R


Portions of the Wechsler Intelligence Scale for Children-Revised (WISC-R) were used in years 1 and 2 to assess child intelligence in early elementary school. The WISC-R was developed by David Wechsler (1974) as a second version of the intelligence scale originally introduced in 1949. For Fast Track, a "short form" of the WISC-R was used which included two of the ten subtests: Block Design (from the Performance module of the WISC) and Vocabulary (from the Verbal Ability module). The short form score was then converted into an IQ score using methods provided by Sattler (1992). This version became part of WISC-R/Woodcock Johnson-R (CxA) in 1992.

Abstract

Portions of the Wechsler Intelligence Scale for Children-Revised (WISC-R) were used in years 1 and 2 for all three cohorts to assess child intelligence in early elementary school. This measure was developed by David Wechsler (1974) as a second version of the intelligence scale originally introduced in 1949. For the Fast Track Project, a "short form" of this measure was used which included two of the ten subtests: Block Design (from the Performance module of the WISC-R) and Vocabulary (from the Verbal Ability module). The short form score was then converted into an Estimated IQ Score using methods provided by Sattler (1992).

Scoring tables from the WISC-R manual were used to create separate age-adjusted scores for the two subtests for year 1. Since test administration dates were not recorded when this measure was given, date of administration from the Family Information Form (FIF) was used as an approximate interview date of this measure as these two instruments were typically administered on the same day in year 1.

The Block Design Raw Score was positively skewed in the normative sample and the high-risk sample. The Vocabulary Raw Score, the Block Design Age-Adjusted Score, the Vocabulary Age-Adjusted Score, and the Year 1 Estimated IQ Score were all normally distributed for both the normative and the high-risk samples.

A limitation for using the IQ score for year 1 is the absence of norms for children under age 6 (Sattler, 1992). Since age-norming tables for this measure have a lower limit of age 6 years, 0 months (age 6-0), scores for children under age 6 in the Fast Track Project were scaled based on the youngest age bracket available (age 6-0 to age 6-3). A substantial proportion of the year one cohort one sample -- 22% of the normative sample and 22% of the high-risk sample -- were under the age of 6.0 years, and thus have potentially inappropriately scaled scores. The result of this in terms of distributions is a mild floor effect and heavier tail for the year one IQ scores.

Depending on the question being addressed, analysts may use the estimated IQ scores or the separate subtest, age-adjusted scores.

Dataset Names

Raw Dataset Name: CyA
Scored Dataset Name: WSRySCc

Keywords

Intelligence Scale, Verbal Ability, Vocabulary, Block Design, Ability