Is IQ-achievement discrepancy relevant in the definition of arithmetic learning disabilities?

This study was designed to test whether the criterion based on the IQ-achie vement discrepancy is useful in the definition of arithmetic learning disab ilities (ALD). A sample of children with ALD, garden-variety (G-V) poor mat hematics performance (i.e., the poor arithmetic performance of children of below-average intelligence is believed to be nondiscrepant, or in accordanc e-with their lower cognitive capabilities) and normally achieving children were selected using the standard-score discrepancy method (i.e., the differ ences between IQ and achievement standard scores). All the groups were comp ared to determine whether there were differences in solving addition and su btraction word problems and in other cognitive abilities related to mathema tics such as working memory. There were no significant differences between children with ALD and children with G-V poor mathematics performance in sol ving arithmetic word problems or on working memory tasks. The performance o f both groups with arithmetic disabilities was significantly below that of normally achieving children. This means that the criterion based on the IQ- achievement discrepancy does not seem to be relevant for differentiating be tween children with ALD and children with G-V poor mathematics performance.