概念的カテゴリーによる分類を促がす教示効果を検討するために2つの実験が行なわれた。実験Iは,4,5,6才のおのおのの年齢群において,概念名辞をまえもって教示される教示群とそのような教示を受けない統制群が設けられた。課題は16枚の絵単語カードを4つのクラスに分類することであり,果物,野菜,花,島の4概念に4枚ずつを分類できるように構成されていた。結果は,概念的カテゴリーによって分類した率(概念的分類率)と分類理由として適切な概念名辞を報告した率(言語化率)によって分析された。そうすると,4,5才児では概念名辞の教示によって概念化が促進されたが,6才児ではそのような教示効果がみとめられなかった。実験IIは,4才半から5才半にわたる年齢群のみについて,実験Iと同じ概念名辞の教示群,事例に共通した特徴を述べる説明的教示群および統制群が設けられた。課題は基本的には実験Iと同じであるが,概念として哺乳類,鳥類,魚類,昆虫類をとりあげ,マッチングによる分類課題が採用された。実験は事前課題,特殊教示,事後課題,転移課題の順に進められ,実験Iと同じ2つの測度によって効果が判定された。その結果,事後課題および転移課題において,概念名辞の教示は概念化を促進するが,説明的教示はそのような効果を示さないことが明らかにされた。これらの実験結果はわれわれの仮説を支持するものであり,言語的媒介の欠如した段階にある幼児に対しては,概念名辞を教示することによって分類の概念化が促がされるといえる。しかもこの種の教示効果は刺激材料に関する観察反応を増すことによるものではなく,明らかに言語反応による媒介効果であることが考察された。

Two experiments were conducted to evaluate the effects of instruction on the conceptual classification of pre-school children. Exp. I was designed to examine the hypothesis that the instruction including conceptual terms would facilitate the conceptualization for classification in the stage of development under which the Ss have not learned to use the terms (hypothesis I). A 2X3 factorial design was used, which incorporated two instructions (the specific instruction given or not) and three age levels (4, 5, and 6 years). 12O children who took part in the experiment were assigned to six groups of 20 subjects each. The Ss in the specific instruction groups were given the terms of supper-ordinate concepts for each instance in addition to the general instruction. After the instruction, the Ss Were requested to classify 16 picture-cards into four categories and to verbalize the reasons for classification. Each card involved one familiar object belonging to one of the four class concepts : fruits, vegetables, flowers and birds. With a considerable modification of the experimental method, Exp. II was carried out to test the hypothesis that the instruction with the conceptual terms would be more effective for classification than the explanatory instruction to describe common distinctive features (hypothesis 2). 57 children from the age of 4.5 to the age of 5. 5 years were divided into three groups of 19 subjects each, equated in age : the group instructed the conceptual terms, the group given the explanatory instruction and the control group. The tasks used in Exp. II were the same as in Exp. I. However, the class concepts were beats, birds, fishes and insects, and the matching method was adopted in pre-and post-tasks. After the pre-task, the Ss were given the specific instruction followed by the post-task and transfer-task. The transfer-task consisted of the different cards from the pre-and post-tasks. The main results may be summarized as follows. 1. The instruction with conceptual terms in Exp. I increased the percentages of both classification and verbal reports on each conceptual category in the age groups of 4 and 5 years, but did not increase in the age group of 6 years. 2. In Exp. II, the instruction with conceptual terms had the same effccts as in Exp. I. The explanatory instruction, however, had no effect on con-ceptualization. These diverse effects according to the instructions Were confirmed not only by the post-task but also by the transfer-task. The results obtained support both hypothesis 1 and 2. A discussion was made on the relationship between the stage of development and the effect of instructiron, emphasizing a role of verbal mediation.