Incidental learning research with mentally retarded children has produced findings inconsistent with those reported for the intellectually normal population. This study was designed to further investigate the efficacy of incidental semantic classification instructions relative to taxonomic classification instructions or superficial color classification instructions with a normal population of children. Forty-four children in grades 2 and 3 were instructed to categorize 18 common pictures by taxonomic category (animals, people, vehicles), by size (big, little, in between), or by color (blue, green, red) in an incidental learning paradigm. The pictures were selected from the Peabody Picture Vocabulary Test. Subjects receiving taxonomic instructions recalled significantly more items and showed significantly better clustering than subjects receiving the other instructions. These results with normal children supported previous Type I incidental learning results with retarded children. (Author/RL)