This dissertation develops a word bank based on a series of well defined filters. The basis of this system is grapheme-phoneme relative frequency control. The word bank is designed to be used in developing reading materials at varied degrees of difficulty. Four short stories were edited as to their grapheme-phoneme relationships. Reading speed and reading comprehension were measured for each student on these stories. All students read a story in the original form and a story in the filtered version. No difference in reading comprehension were found, but reading speed was significantly higher on three of four stories.