This study was designed to select and explore a research battery which, when administered at the beginning of the school year, more adequately and efficiently predicts end-of-year reading achievement than have previously used tests and test batteries. The most powerful predictor tests were designed to provide a more adequate screening device than is currently available for the use of classroom teachers in grouping for reading instruction. A second major purpose of this study was to explore the relative contributions of perceptual-motor and cognitive intellectual ability measures at the first and third grade levels of reading instruction in order to suggest guidelines for instructional emphasis in teaching reading skills. Two hundred and four first grade students and 202 third grade students were divided into validation groups and tested with various combinations of perceptual-motor tests and cognitive-intellectual tests at the beginning of the year. Their scores were correlated with their reading achievement scores at the end of the year with the higher correlations indicating the more effective batteries. Results indicate that perceptual motor tests were better predictors of reading achievement scores for first grade children while cognitive-intellectual tests were better for third graders. (DJ)