MULTIPLE ORTHOGRAPHIC CODES IN READING AND WRITING ACQUISITION

A modified Stroop Test (single-letter, letter-cluster, and whole-word colorinconsistent stimuli) showed greater interference for the more automatic orthographic coding unit-the word-than for the less automatic coding units-single letters and letter-clusters-in developing readers in second, fourth, and sixth grade (N=72, Study 1). A developmental trend was observed from relative skill in word-level orthographic-phonological correspondence in second graders to relative skill in subword level orthographic-phonological correspondences in sixth graders. A previous finding that whole word coding > letter coding > letter cluster coding in relative rate of development was replicated (N=300, Study 2). Multiple orthographic codes-for whole words, single letters, and letter clusters-were correlated with both reading and writing but patterns of correlations with the component reading and writing skills changed from first to third grade; by third grade whole word coding was not correlated with reading and writing skills but letter cluster coding was correlated with all reading and most writing skills. Cue validity -categorization of letters on the basis of differentiating rather than distinctive features-improved from second to sixth grade and may account for developmental gains in letter cluster coding. Level of cue validity was correlated with speed of sentence comprehension (N=60, Study 3). The theoretical and practical significance of multiple orthographic codes for orthographic-phonological connections in word recognition and for literacy acquisition in general is discussed. © 1991 Kluwer Academic Publishers.