On publishing

The Hart and Risley (1995) study is an influential one. The book has had at least six printings, it is endorsed by leading educational figures, and its findings are widely cited. In essence, Hart and Risley’s thesis is that the amount of language that young children hear affects their vocabulary size. Hart and Risley’s three major conclusions (pages xixxx) are (1) families differ greatly in the quantity of speaking that occurs with children, (2) quantity of speaking is linked to growth in vocabulary size, and (3) quantity of speaking is linked to the amount of quality features in the language used. The following diagram shows how the conclusions are related to each other.