The purpose of this study was to see developmental aspect by age, focusing on whole-object assumption and taxonomic assumption.
When children learn a new word, whole-object assumption is to assume that new word refers to the whole object itself. Taxonomic assumption is to assume that one object refers to the category that includes those things.
The subjects of the study included 103 children in total: 24 normal children at the age of 3, 22 normal children at the age of 4, 34 normal children at the age of 5 and 23 normal children at the age of 6.
Two experiments were conducted for this study. Experiment 1(mutual exclusive assumption and whole-object assumption): Researcher asked children to select one among 4 picture(whole stimulus, part of whole stimulus : stimulus of known name, ambiguous-whole stimulus and part of ambiguous stimulus: stimulus of unknown name) when novel non-word used. Experiment 2(taxonomic assumption): Researcher asked children to select one between 2 pictures(thematic relations with target picture and taxonomic relations with target picture) that were the same as the target when novel non-word used to the target picture.
Result of mutual exclusive assumption: Stimulus of unknown name was selected most frequently by the age of 3~6. In 5-year-old, children hearing a new word selected a stimulus of unknown name significantly more than a known name.
Result of whole-object assumption: Ambiguous-whole stimulus was selected most frequently by the age of 3~6. But children at the age of 3~4 preferred to ambiguous-whole stimulus and whole stimulus, children at the age of 5~6 preferred to ambiguous-whole stimulus and part of ambiguous stimulus.
Result of taxonomic assumption: when children heard a new word, all groups tended to choose the taxonomically related picture more often than a thematically related picture. However, the frequencies of selected 2 stimuli were similar at the age of 3~5. In 6-year-old, children hearing a new word selected a taxonomically related picture significantly more than a thematically.
The result of this study found that normal children at the age of 3~6 infer the meaning of new word by using mutual exclusive assumption, whole-object assumption and taxonomic assumption. In the developmental aspect, mutual exclusive assumption and whole-object assumption were established at the age of 3 and taxonomic assumption was established after the age of 6. Therefore, if children over 3 years old show difficulty to use mutual exclusive assumption and whole-object assumption or children over 6 years old show difficulty to use taxonomic assumption, it is suggested that the word learning may be delayed.