New norms for the Minnesota Child Development Inventory (MCDI) are pre
sented. The present study focussed on children ranging in age from 1 t
o 4 years, considered by many to be the most crucial period for conduc
ting developmental screening. The final sample (N = 1,322) was three t
imes larger than the original MCDI sample for the same ages (1 - 4 yrs
), and represented a broader range of demographics. No relationship wa
s found between medical history and SES, and MCDI scores. As an altern
ative to the percentage cut-off method of determining developmental st
atus, the larger sample allowed the calculation of means and standard
deviations for each age. T-scores may be derived from this information
. The new normative sample was found to fit the theoretical normal cur
ve remarkably well. Illustrative case reviews consistently demonstrate
d that the use of the SD versus percentage cut-off method yielded diff
erent developmental profiles. The new norms represent a substantially
larger, more demographically diverse sample, from which a more standar
dized psychometric description of performance may improve use of the M
CDI in developmental assessment.