Using a semantic mapping technique for vocabulary instruction, a study explored how children of diverse groups bring different cultural backgrounds and prior knowledge to tasks involved in learning new words. The study was conducted in three sixth-grade classrooms--one containing rural Native American (especially Menominee) children, another containing inner-city Black children, and the third containing suburban Caucasian children. The 20 words chosen for semantic mapping instruction were chosen from four categories: animals, recreation, health care, and environment. It was anticipated that the subjects would learn the vocabulary words by relating the target words to words already in their vocabularies. One 30-minute semantic mapping vocabulary lesson was taught each of four days. Analyses were done through interview procedures designed to examine the linkages between cultural background, prior knowledge, and the acquisition of new vocabulary. Measures of dominance indicated that (1) Caucasian subjects offered the highest average number of categories per map on all maps, and the highest average number of words on all but the health care map; (2) Black subjects offered the lowest average number of categories on all maps, and the lowest average number of words on all but the environment map; and (3) Native American subjects offered the highest number of words on the health care map, and the lowest average number of words on the environment map. (Appendixes include the semantic maps, the validation test and directions for administration, a sample lesson plan for animals, the interview protocol, and the retention test.) (HOD)