Rasch analysis of the Bruininks-Oseretsky Test of Motor Proficiency-Second Edition in intellectual disabilities.
The 36-item BOT-2 is a faster, more accurate motor test for kids with intellectual disability.
01Research in Context
What this study did
The team took the full 53-item BOT-2 motor test and ran it through Rasch analysis. They tested the kids with intellectual disability years. The goal was to find which items actually measure motor skill in this group and which ones just add noise.
They looked at how each item fit the model and how well the test separated mild from severe motor delays. Items that misfit or showed bias were marked for removal.
What they found
Seventeen items misfit and were dropped. The new 36-item version kept all the key motor skills but worked better. Reliability jumped to 0.90-0.97 across subtests.
The shorter test could now tell apart kids with mild versus severe motor delays more clearly than the original. Test time dropped without losing accuracy.
How this fits with other research
This work builds on Hastings et al. (2001) and Oliver et al. (2002) who refined the DBC checklist for kids with ID. Like them, Yee-Pay et al. used modern stats to make an existing tool work better work better for this population.
Balboni et al. (2014) later did the same thing with the DABS adaptive behavior scale. All three papers show that standard tests often need tweaks to be fair for kids with ID.
The pattern is clear: take a mainstream tool, test it with ID samples, then trim and tune. Each paper adds to the toolkit BCBAs can trust when working with this group.
Why it matters
You can now use the 36-item BOT-2 instead of the full 53-item version. It saves 10-15 minutes per child and gives clearer data. When you need motor skill baselines for kids with ID, this refined tool is your best bet.
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02At a glance
03Original abstract
The Bruininks-Oseretsky Test of Motor Proficiency-Second Edition (BOT-2) is widely used to assess motor skills for both clinical and research purposes; however, its validity has not been adequately assessed in intellectual disabilities (ID). This study used partial credit Rasch model to examine the measurement properties of the BOT-2 among 446 children and adolescents with ID aged 4-18 years. Seventeen items were identified as problematic in the Rasch modeling. After removal of these items, the appropriateness of the response categories was examined in the 36 remaining items. Where the item response categories failed to express an increasing level of the trait (disordered thresholds), collapsing adjacent categories was performed to address this issue. After rescoring most items, items in each composite of the revised BOT-2 showed good fit to the Rasch model and demonstrated excellent reliability (range 0.90-0.97). No differential item functioning was detected with respect to age and gender. The ability of the revised composites to differentiate between mild versus moderate to severe ID was better than those of the original BOT-2. Items from the manual coordination and strength and agility composites were well targeted to the sample, whereas items from fine manual control and body coordination composites were mostly targeted at the lower levels of ability in these domains. Items of higher difficulty may be supplemented to increase the range of ability levels of the people to whom these two composites can be applied with precision.
Research in developmental disabilities, 2009 · doi:10.1016/j.ridd.2009.03.003