Subtypes of Mathematics Disability: A New Classification Method Based on Cognitive Diagnostic Models and Their Cognitive-Linguistic Correlates

This study aims to classify subtypes of mathematics disability (MD) using a novel classification method, cognitive diagnostic models (CDMs), and examine whether domain-general skills, namely, linguistic, working memory, and spatial skills, were related to the identification of the subtypes. Participants were 454 children (246 boys; age: M ± SD = 88.66 ± 5.92 months), including 204 MD children and a control group of 250 low-achieving children, who were identified from a sample of 3,384 second graders in China. Six MD subtypes were classified: the symbolic and concept deficits group, the verbal and concept deficits group, the pervasive deficits group, the concept deficits group, the mapping and concept deficits group, and the unknown deficits group. The reliability and validity of using CDMs to identify MD subtypes were evaluated. Different constellations of working memory, spatial, and linguistic skills were found to contribute to different MD subtypes. Identifying subtypes of MD and their domain-general correlates sheds light on appropriate interventions targeting different MD subtypes.