What are the Bayley Scales of Infant Development? What do the scale assess, in particular,

what types of motor development are measured?  How can the scale be used for research
purposes?

What will be an ideal response?

The BSID is a standardized, norm-referenced test that assesses infant mental and motor
abilities from 2 to 30 months of age. In terms of motor development, the BSID assesses
both fine and gross motor abilities. The BSID works well in differentiating many types
of infants on motor abilities, for example, preterm infants frequently score lower than
their full-term counterparts for some time on this instrument. Unfortunately, the BSID
does not forecast long-range competencies in children. However, it is widely
recognized as a very good instrument to determine the infant's current developmental
status.