Psychometric properties of process assessment of the learner (second edition): Diagnostics for math among Iranian...

Process Assessment of the Learner (Second Edition): Diagnostics for Math (PAL-II M) is a diagnostic tool for Math Learning Disability (MLD) with 14 subtests assessing specific math skills and math-related skills. This study examined the psychometric properties of PAL-II M and compared the performance of children with and without MLD.

The PAL-II M and the Learning Disability Evaluation Scale (LDES) were used as assessment instruments. The sample included 404 primary school students from Tehran and 95 children diagnosed with MLD.

The results confirmed the reliability of all subtests, except the Fingerprint Writing subtest. A three-factor model provided the best fit for the data, diverging from the original two-factor structure proposed for the test. Significant differences were found in PAL-II M scores between groups with and without MLD. Quantitative and spatial working memory were the strongest differentiators between the groups (χ² = 213.8, p < 0.001).

The PAL-II M demonstrated strong psychometric properties and a cohesive factor structure among Iranian students. The subscales in PAL-II M are better categorized based on specific neuropsychological functions, including processes related to calculation, visual-spatial processing, and numerical processing. Furthermore, the test effectively distinguished between children with and without MLD. The interrelationships among PAL-II M subtests align with the various subtypes of MLD. Conceptualizing mathematical competency as a cohesive process encompassing general neuropsychological functions and specific learned mathematical skills is advantageous.