The methods and validity of evaluations of cognitive development, in language and numbers, of children ages three through six, by use of classroom observation inventory lists are discussed. The Evaluation of Cognitive Development--Pre-Reading Skills, an observational instrument (teacher completed), was administered to 134 first grade students in a Gulfport (Mississippi) project in order to determine the presence of 64 behaviors regarded as significant in evaluating pre-reading skills. Thirty-two behaviors were exhibited by all or nearly all of the students. A factor analysis of the remaining 32 variables yielded eleven that were strongly associated with achievement and readiness. These variables were placed into two general categories: behavior associated with interaction with other children, and behavior relating to phonic discrimination. Thus, the results indicate that certain social behaviors and behaviors reflecting phonics ability were clearly related to reading readiness and achievement even late in the first grade. Whether this behavior pattern is applicable to the population of other grade and age levels is yet to be determined. A longitudinal study, as well as additional performance validity of the eleven variables, in the age group three to six, is recommended. (AE)