Measurement of clinically significant change is critical for rehabilitation research because it can enhance the credibility of rehabilitation efforts and guide evidence-based practices. The practical appeal of clinically significant change is that it can bridge research and clinical practice by focusing on individual rather than group differences.…

This paper identifies typical sampling problems, including improper application of the Central Limit Theorem, that are associated with the probability-based sampling procedures currently used in clinical psychology research. It then presents two alternative research designs, the theory validation model and the extended case study model, which…