Purpose: The purpose of this study was to analyze the effects of an increased number of practice trials on scores on the Gross Motor Scale of the Peabody Developmental Motor Scales (PDMS) among preschoolers who are typically developing. Performance-based assessment tools such as the PDMS generally allow for limited practice.
Methods: Nineteen children between the ages of 48 and 68 months participated in the study. The PDMS was administered to each subject on a single test occasion, with up to five trials allowed and scored for each task. Analysis included the percentage of change in scores, identification of differences among mean scores per number of trials using multivariate analysis of variance, and potentially clinically significant change using confidence intervals.
Results: All mean raw gross motor domain and total scores with three to five practice trials were significantly different (p < 0.001) from scores attained with standard administration of the PDMS. The largest score increases occurred in the domain of receipt and propulsion. Almost 50% of the subjects demonstrated potentially clinically significant improvements with five trials.
Conclusions: We question the validity of scores received by preschoolers for receipt and propulsion tasks used in the PDMS and suggest reexamination of such tasks. Allowing practice trials during administration of all tasks on the PDMS with preschoolers may allow them to achieve scores reflective of their optimal performance.