In order to see if an extended-day kindergarten program has a greater effect than a half-day kindergarten program on reading achievement in the first-grade, a study compared standardized test scores of two different groups of first-grade students. Subjects, a group of 44 students who had participated in a half-day kindergarten program and a second group of 80 students who had participated in an extended-day kindergarten program, were administered the Science Research Associates Achievement Series (SRA). Results indicated that the scores of the children in the extended-day kindergarten were higher than the scores of the children in the half-day kindergarten program, although the difference in scores was not statistically significant. (A table of data is included, and 13 pages of a related research review, 23 references, and an appendix containing the subjects' SRA scores are attached.) (JK)