Word Frequency and Reading Comprehensiony1

It was hypothesized that by varying the frequency of 15 percent of the words in elementary school reading materials, gains in the comprehension of the meaning of entire passages could be produced. To test this hypothesis, 222 sixth graders were randomly assigned to two reading treatments, presented simultaneously in the same room, differing only in the frequency of 15 percent of the words used in the stories. Reading comprehension was significantly increased (p > .0001) with high frequency story passages. Results indicated that increases in the frequency of a small percentage of words enhanced story comprehension, while a few less familiar words inhibited comprehension of the total passage. The data suggest that, in the design of reading materials for use in elementary schools, sizable increases in reading comprehension can be produced by increased attention to the semantic variable of word frequency.