Children's memory for phonemically confusable and nonconfusable letters: changes with age and reading ability.

This experiment focused on differences that occur with age and reading skill in the use of phonemic codes in short-term retention tasks where stimuli were presented visually. In 1 condition, individuals recalled 6-letter strings composed of rhyming and nonrhyming letters after a 15-sec delay under conditions that permitted phonemic coding and rehearsal. 2 other conditions were designed to suppress (a) rehearsal of certain types of phonemic codes in the delay interval and (b) both phonemic coding at stimulus presentation and rehearsal. Subjects were grade 2 average readers matched in reading skill with grade 4 disabled readers, grade 4 average matched with grade 6 disabled, and grade 6 average matched with grade 4 superior readers. Average readers showed a decrease in errors with age in all 3 conditions, although performance was always better in the nonsuppression condition. In the latter, memory for nonrhyming letters was always better than memory for rhyming letters. Differential use of phonemic codes by good and poor readers in grades 4 and 6 was less than that found in previous research with younger children. Finally, by comparing the performances of grade 2 average with grade 4 disabled readers and grade 4 average with grade 6 disabled readers, the developmental lag hypothesis of reading disability was examined. Problems with testing the hypothesis are discussed.