The reading progress of 96 disadvantaged children from kindergarten through grade 3 was analyzed to determine rate and consistency of reading growth as estimated from several reading measures. Although steady growth was observed on all measures, rate and consistency varied with the type of reading measure used, as well as with the specific test series. The Metropolitan Achievement Tests and the New York Tests of Growth in Reading yielded consistently higher scores than did the two informal measures, the Harris Graded Word Lists, a measure of sight vocabulary, and the highest level of book used in the classroom. The New York Tests appeared to yield somewhat higher scores than did the Metropolitan Tests. Acceleration appeared greater in the first and second grades on the standardized measures and in the third grade on the informal measures. There was approximately a one grade discrepancy between the frustration level estimated by standardized tests and the instructional level estimated by informal measures. It was concluded that standardized test results seem best suited for assessing the achievement growth of individuals and groups, while informal measures are probably best suited for determining each child's functioning level and for selecting materials. Tables are included. (Author/DH)