A critical review of the literature on NLD as a developmental disorder.

The extant research on nonverbal learning disability (NLD) was analyzed in this review. Studies were defined for use in the review as those that appeared in a peer-reviewed journal and included participants characterized as having NLD. Each study also needed to provide a statistical analysis of dependent variables. An a priori system was used to evaluate the quality of the research. Of the 88 publications found, 32 met criteria for inclusion in the review, with 6 meeting full criteria as strong studies. The diagnostic criteria used and the research findings are briefly discussed, as are proposed guidelines for future research.