Construct validity of the Test of Visual-Motor Skills-Revised (TVMS-R): an evaluation using the Rasch Measurement Model.

Construct validity of instruments, tests, and scales can be examined using the Rasch Measurement Model (RMM) during their initial construction and validation, or after they have been published. The aim of this study was to examine the construct validity of the Test of Visual-Motor Skills-Revised (TVMS-R) by applying the RMM to evaluate its scalability, dimensionality, differential item functioning, and hierarchical ordering. The participants included 400 children aged 5 to 12 years, recruited from six schools in the Melbourne metropolitan area, Victoria, Australia. Children completed the TVMS-R under the supervision of an occupational therapist. Overall, 39 out of 142 of the TVMS-R scale scoring accuracy classification criteria items exhibited poor measurement properties. As nearly one-third of the scoring classification criteria items were found to be problematic, the TVMS-R in its current form is not recommended for clinical use, as it is not consistent with the clinical demands expected of an instrument used to evaluate the visual motor integration skills of children.