Accordingly, PRI includes three core subtests: Block Design, Matrix Reasoning, Visual Puzzles, together with Figure Weights and Picture Completion as supplemental subtests. The VCI includes three core subtests: Similarities, Vocabulary, Information and Comprehension as a supplemental subtest. The indices are composed by sets of subtests identified as core or supplemental.
WAIS IV SCORING MANUAL SIMILARITIES FULL
Each index scale contributes to a composite score that represents general intellectual ability, the Full Scale IQ (FSIQ). The test framework of the WAIS-IV provides composite scores that represent intellectual functioning in four specific cognitive areas: Verbal Comprehension Index (VCI), Perceptual Reasoning Index (PRI), Working Memory Index (WMI), and Processing Speed Index (PSI).
WAIS IV SCORING MANUAL SIMILARITIES UPDATE
The WAIS originates in the Wechsler‐Bellevue Intelligence Scale (1939), revised and modernized into the following versions: the Wechsler‐Bellevue Form II (1946), Wechsler Ault Intelligence Scale (1955), Wechsler Ault Intelligence Scale – Revised (WAIS-R, 1981), WAIS‐III (1997) and WAIS‐IV (2008), which is the most recent update of the scale. It has also been described as the “work horse” in clinical assessments (Crawford, Allum, & Kinion, 2008). One of the internationally most frequently applied neuropsychological test batteries is the Wechsler Adult Intelligence Scale (WAIS) (Ryan, Kreiner, Gontkovsky, & Glass Umfleet, 2015). Otherwise, this model and the four-subtest model are recommended to be used with caution. Applied on the Swedish version of the WAIS-IV the seven-subtest formula appears to be applicable on an FSIQ level, to be suitable for a younger sample, but not for an elderly.
The best reduction of the seven-subtest short form was a four-subtest model, encompassing Block Design, Similarities, Arithmetic and Coding, one subtest from each index, but the t-tests indicated several cases of mismatches between the full WAIS-IV measures and the prorated scores. In the younger and middle aged sample (<55 years) results on FSIQ as well as index level were in accordance, whereas in the elderly group (∼55 years) they were incongruent.
When the original WAIS-IV was compared to the seven-subtest short form the results showed a good congruence on FSIQ-level between the two sets, but on index level there were several cases of mismatches. WAIS-IV data from a non-clinical sample consisting of 261 participants ranging between 18 and 74 in age was analyzed with bivariate and multiple regression analyses, a prorating method for calculation of Full Scale IQ (FSIQ) and its indices as well as paired-samples t-test. The study aimed at investigating whether the seven-subtest short form based on WAIS-R (Ward 1990) was statistically valid to use on the Swedish version of Wechsler Adult Intelligence Scale, Fourth Edition (WAIS-IV), if this abbreviation was fit to catch the heterogeneity in test performance across age and if this brief measure was possible to abbreviate even more.