Digits forward and digits backward as two separate tests: Normative data on 1567 school children

Abstract

Abstract Although Wechsler's decision to combine the Digits Forward and Digits Backward sections of the Digit Span subtest of the WISC (and WISC‐R) was justifiable regarding their utilization in a general test of intelligence, such combination may deprive the examiner of important information that could have been derived from the separate data. Specifically, the Digits Backward operation usually requires the subject to form an internal visual engram from the auditorally presented numerical sequences and, in addition, to utilize both forward and backward visual scanning mechanisms. The Digits Forward section may be successfully accomplished without such operations, especially for the short numerical sequences. The Digits Backward section, then, can be a useful test of certain aspects of visual processing, and therefore of particular value in the diagnosis of children with neurologically based learning disabilities (who so often suffer with impairments in this area). Separate data for Digits Forward and Digits Backward were collected on 1567 school children (782 boys and 785 girls). Means, standard deviations, and percentile ranks are presented for each of these two sections of the Digit Span subtest, enabling the examiner to utilize each section as a separate diagnostic test.