Structural validity of the Bruininks-Oseretsky test of motor proficiency – Second edition brief form (BOT-2-BF)

Background: Practitioners often assess the motor skills of children presented with suspected developmental delays. It is essential that the tests used to assess children have strong measurement properties including validity. Aim: The structural validity of the Bruininks-Oseretsky Test of Motor Proficiency – second edition Brief Form (BOT-2-BF) was investigated. Method: 123 healthy children (67 males & 56 females; M = 10 years, 2 months; SD = 1 year, 4 months) completed the BOT-2-BF. The Rasch Measurement Model (RMM) was used to assess the 14-item BOT-2-BF's dimensionality, hierarchical ordering, differential item functioning (DIF), and item and person separation reliability. Results: Nine BOT-2-BF misfit RMM requirements. A second RMM analysis of a five-item BOT-2-BF version was completed. The five-item version did meet the RMM requirements of item fit, dimensionality, hierarchical ordering, lack of DIF, and adequate item and person separation reliability. Implications: The 14-item version of the BOT-2-BF is not recommended for use as a screening scale to assess children's motor skill performance. However, a revised five-item version of the BOT-2-BF did appear to meet RMM expectations. Further psychometric assessment of the revised five-item version of the BOT-2-BF is recommended.