One of a series of reports evaluating the Durham Education Improvement Program, this study concentrates on assessing the influence of age-of-entry on subsequent changes in performance on intelligence tests. Changes in intelligence quotient scores for two age-at-entry groups (3-, 4-, 5-year-olds combined and 6-year-olds) were correlated after one and two years of participation in the program. Although significant increases in measured intelligence were found after both one and two years in the program, no one entry age afforded greater increases in scores than another. (Tables are included). (WY)