This thesis suggests a new method of developing reading materials for Navajo students. The core of this method is based on phoneme- grapheme relative frequency correspondence data. A short story was phonetically edited and rewritten using the phoneme-grapheme relative frequency method. This short story was one of the major products of the thesis. This short story and three other short stories previously phonically rewritten, were presented in both this form and in original text to 38 Navajo students for reading. Reading speed and reading comprehension were measured for each student on the short stories. The students performed with superior reading speed and with superior reading comprehension on two stories and equal comprehension on two stories. The difference on reading speed was significant at the .01 level. On the two stories with reading comprehension differences, the difference was significant at the .05 level.

The ability of students to segment the speech stream into phonemic units and to analyze (make judgments as to same or different) beginning consonant phonemes was assessed at grades kindergarten through third from both high and low socioeconomic groups. Segmentation ability was assessed by the use of a test of actual words in a match-to-sample task, a test of synthetic words requiring a same-different judgment and a task which required deletion of a phoneme from a known word to form a new word. Three prerequisite abilities were also assessed: auditory acuity and understanding of the concepts "same" and "different" with regard to sounds, and "beginning" with regard to sequence of sounds.

This dissertation suggests a new approach to reading instruction and phonetic control in materials development. The central feature of this approach is its reliance on phoneme-grapheme correspondence data. Specifically, the products of this dissertation were (1) the development of relative frequency tables depicting the various phonemes produced by a given grapheme structure, (2) the development of five different levels of phonetic sophistication, (3) the classification of 974 words as regular or irregular in accordance with each level of sophistication, and (4) the phonetic rewriting of three existing short stories to make them phonetically regular. One of the phonetically rewritten stories was given to an existing group of sixth grade students along with its original form. The students performed with superior reading speed and equal comprehension on the phonetically rewritten story. This difference was significant at the .01 level.