The Daviess County, Kentucky, PREPS research project focused on evaluating the county's 1979 summer school program. This program invited children to attend if they were functioning at least one year below their grade placement level. Learning activities were structured around specific behavioral objectives; the emphasis was on reading and mathematics. The evaluation of the program consisted of analyzing whether reading and mathematic achievement were significantly related to attendance in summer school, and whether this relationship was equally true for boys as well as for girls. When all summer students were contrasted against non-summer school students, significant differences were found only at the grade 2 level in reading; in addition, summer school was helpful for grade 2 girls in mathematics. (Author/GK)