 The most significant revision to the Bayley-III is the development of five distinct scales (as compared to three scales in the BSID-II) to be consistent with areas of appropriate developmental assessment for children from birth to age 3.Whereas the BSID-II provided Mental, Motor, and Behavior scales, the Bayley-III revision includes Cognitive, Language, Motor, Social-Emotional, and Adaptive Behavior scales.Considering that the primary intent of the Bayley-III is to identify children experiencing developmental delay and not to specifically diagnose a disorder, the floor and ceiling of the subtest and total test appear to be adequate.