Error patterns in math computation among boys with attention-deficit/hyperactivity disorder and learning disabilities

A growing body of research documents the overlap in the number of children who exhibit both ADHD and LD and provides evidence for the distinction between these two disorders based on a number of cognitive and neuropsychological variables. The present study attempted to further the research to differentiate between children with ADHD and children with LD by using an academic variable, similar to academic tasks that children encounter in school. Specifically, the purpose of this study was to examine the math computation performance associated with ADHD and LD. This was accomplished by employing an error analysis procedure on the Diagnostic Test of Arithmetic Strategies (DTAS) to identify specific types of errors made by four groups of boys (ADHD, ADHD/LD, LD, NC) in the areas of addition and subtraction computation. Subjects included 17 boys diagnosed with ADHD, 11 boys with a math LD diagnosis, 16 boys with both ADHD and a math LD diagnosis, and 15 normal comparison boys. These four groups were compared on errors categorized as slips, bugs, number facts, and writing/alignment as well as on the number of total errors made.;Nonparametric Kruskal-Wallis H tests were conducted for each dependent variable of error categories followed by pairwise comparisons using Mann-Whitney U tests on those variables where the Kruskal-Wallis one-way ANOVA was found to be significant. Since groups differed with respect to SES, it was used as a covariate for comparisons involving variables that correlated significantly with SES. In addition, effect sizes were calculated for all pairwise comparisons.;In general, there was partial support for the idea that ADHD, LD, ADHD/LD, and NC boys can be differentiated by the types of errors made on a math computation task. Significant differences were found among groups on several error types: LD boys made significantly more bugs, number fact errors, and total errors than ADHD boys and NC boys. Additionally, ADHD and ADHD/LD boys made significantly more slips than NC boys. The possibility of further significant findings may have been obscured by the small sample size and relatively low statistical power. Results are discussed in terms of research and practical implications, and suggestions are provided for future research.