ISSN : 1229-0718
Three experiments were carried out to test whether 4-and 5-year-old children can solve the class inclusion problem, using class, collection and compound noun labels. In experiment 1, children's performance was better with collection and compound noun labels than with class labels, even though their correct response rates were lower them 30%. In experiment 2, the relation between parts and whole was explained more explicity. The facilitative effects of collection and compound noun were found in both ages. The correct response rates for collection and compound noun labels were higher than 80% in 5-year-old children, and lower than 50% in 4-year-old children. In experiment 3, 5-year-old children were taught about the hierarchical class inclusion relation using nonsense compound noun and single noun labels. There were more correct response when the compound noun labels were used than when the single noun labels were used. These results indicate that 5-year-old children can solve class inclusion problem and that compound noun and collection labels facilitate the children's understandings of the hierarchical class inclusion relations among categories.