Orthographic context and the acquisition of orthographic knowledge in normal and dyslexic readers.

We tested the hypothesis that the acquisition of orthographic knowledge of novel words that are presented in an indistinct context, that is a context with many orthographically similar words, would be more difficult for dyslexic than for normal readers. Participants were 19 Dutch dyslexic children (mean age 10;9 years), 20 age-matched and 20 reading-age-matched normal readers. During training the children repeatedly read a series of nonwords in a distinct (KWOG with KWES and SNAR) and an indistinct (KWOG with KWOS and KROG) orthographic context. At posttest, the dyslexic children were slower but more accurate in the reading of nonwords if these had been acquired in an indistinct than in a distinct training context. In normal readers context did not have an effect. We argue that dyslexic children's sensitivity to orthographic context is due to their problems in the acquisition of fully specified orthographic representations causing interference by similar words.