Convergent Validity Between Two Motor Tests: Movement-ABC and PDMS-2

The aim of this study was to investigate the convergent validity of the Movement Assessment Battery for Children (M-ABC) and the Peabody Developmental Motor Scales - 2 (PDMS-2). Thirty-one 4- and 5-year-old children (mean age 4 years 11 months, SD 6 months), all recruited from a clinical setting, took part in the study. Children were tested on the M-ABC and the PDMS-2 in a counterbalanced order on the same occasion. The results showed that the total scores on the two tests correlated well (rs = .76). However, when the ability of the two tests to identify children with difficulties was examined, agreement between them was low (K = .29), with the PDMS-2 being less sensitive to mild motor impairment in this population. Taken together, these findings suggest that clinicians need to be aware that, although measuring a similar construct, these tests are not interchangeable.