言語音を文字で書きあらわすことができるためには,どのような条件が必要であるかを調べた。実験Iでは,単音節の音声に対応していた文字反応(構成)ができることが直ちに2音節の音声に対して文字反応ができることを意味しないという結果が示された。被験児はこの段階では,絵カードと文字カードを対応させたり,2音節言語音を文字カードと結びつけることがごくわずかしかできていない。また,文字カードの文字を読んだり,絵カードの絵の名称を発音することもほとんどできないことがわかった(実験I-(a)〜(d))。そこで,これらを学習させる条件を導入すれば正の文字反応がなされるかどうかを調べた。実験IIで,絵カードと文字カードの結合および絵の名称の発音を同時に学習させた結果,文字反応が可能であることがわかった。次に実験IIIで,絵カードと文字カードの結合を学習させ,これの効果を調べた結果,約70%の正反応が得られた。しかし実験IVで,絵の名称の発音を学習させたが,正反応は全く得られなかった。以上の結果より,実験IIにおける学習が文字反応に効果をもたらすことが明らかになったが,被験児は発音の学習に困難が伴なうので,異なる学習が導入された。実験Vでは,まず文字カードの各文字を1字ずつ区切って読ませる。発音の正否は問わず,被験児が読めなければ復唱させ,次に絵カードに結びつけさせる。更に,絵カードを呈示して文字カードの中から選択させる。この学習ができた後に,2音節の言語音に対応する文字反応をやらせた結果,100%の正反応を得た。従ってこの学習条件は,本被験児が文字反応を行うのに実験IIにおける学習より有効であると言える。

The present paper describes the way a child learns how to put given speech sounds into Japanese phonemic letters (hiragana). The subject, N, is an ll-year-old boy and attends school for mentally retarded children. He has difficulty in communicating with others, especially in expression rather than in reception. He had already learned to write several single letters each of which corresponds to one-syllable sound when the following experiment was started. In Experiment I, N was required to write two letters, receiving a two-syllable sound which consisted of letters he had learned. He was given three lists of sounds each of which included twelve two-syllable sounds. The result showed that though N could write a single letter corresponding to a one-syllable sound did not guarantee he could do so when he was given a two-syllable sound. In Experiment I-(a)-(d), he was required to match picture cards with letter cards (a), to choose the letter cards equivalent to the speech sounds he received (b), to tell the names of the pictures on the cards (c) and to read the words on the cards(d).The words used were the same in Experiment I. He could perform only a few of the above four experiments. In Experiment II, it was investigated whether N could write two letters corresponding to a given twosyllable sound after he had learned he had failed in both Experiment I-(a) and (c). He could perform the task completely. Next, it was examined whether he could write letters with a two-syllable sound while being told his failure in Experiment I-(a) (Experiment III) and in Experiment I-(c) (Experiment IV) respectively. In Experiment III, he responded approximately 70 percent correctly and in Experiment IV, he made no correct answers. The items used were twelve words (one list) in Experiments II, III and IV. These results showed that the learning in Experiment II was indispensable in order to write two letters corresponding to the sounds. But as N had difficulty in telling the name of the pictures, he needed to be given a different kind of learning procedure. In Experiment V, N was required to read two letters (a word) on a separately given card, then, to choose a picture card equivalent to them, and in addition, to make correspondence between the picture card and the letter card. The items used were twelve new words. With this learning, N was able to write two letters completely, receiving a two-syllable sound. This learning procedure was found to be more useful to him than the one described in Experiment II.