This study examines the evolution of psychoeducational assessment tools for evaluating cognitive characteristics in children with developmental disabilities, focusing on neuropsychological theories and their practical applications in Japan. Two major theoretical frameworks are discussed: the PASS theory (Planning, Attention, Simultaneous, and Successive processing) and the CHC theory (Cattell-Horn-Carroll). The PASS theory, derived from Luria's brain function theory, is operationalized in tests like DN-CAS, enabling strength-based teaching strategies. The CHC theory, represented in tests like WISC-V, provides a hierarchical model of cognitive abilities. Both theories contribute to comprehensive cognitive assessments and targeted interventions. Recent developments include the integrated SNP/CHC model, which combines school neuropsychology and CHC theory, facilitating a more holistic approach to assessment and intervention. The study also highlights Japanese research on EEG coherence patterns during DN-CAS subtests, revealing distinct neural mechanisms for simultaneous and successive processing. The paper emphasizes the importance of process assessment and strategy evaluation, particularly in planning tasks. It concludes by discussing the need for further research to strengthen the connection between assessment results and educational interventions, aiming to enhance support for children with developmental disabilities in Japan.