Extrapolated developmental indices for the Bayley Scales of infant development.

Regression equations from the normative sample data of the Bayley Scales of Infant Development were derived and raw scores corresponding to Mental and Psychomotor Developmental Indices below 50 were computed. Extrapolated values are useful for estimating a child's present level of functioning, but because they are not based on empirical data, they should be considered estimates and used cautiously.