Zone of Proximal Development

子どもは周りの社会-文化的環境に助けられて言語も習得するというポイント（Zone of Proximal Development: ZDP)を印象的にするために、Leo van Lier (2004) The Ecology and Semiotics of Language Learning: A Sociocultural Perspective. Kluwer Academic Publishers: Bostonの37ページで使われた表現です。思わず笑ってしまったので、ここに掲載しておきます。

For example, if in response to the baby's "Goh!" above the adult had responded: "Notice, small fellow, that this particular canine, which you have somewhat amgiguously referred to as 'Goh,' -- presumably your immature approximation of the word 'dog' -- is of the sub-species 'mutt,' characterized by crooked paws and lopsided ears, found originally in the foothills of Neasden, and recently promoted to the status of domestic companion in the Bavarian hinterland," the baby might not have made much headway linguistically, cognitively or socially, in spite of the vastly superior level of information provided. The close connection between the learners' actions and the adults' rejoinder relates to the notion of the ZPD.

http://en.wikipedia.org/wiki/Zone_of_Proximal_Development