The research described in this proposal is designed to provide new information about both preventive and remedial instructional strategies for children with phonologically based reading disabilities. The research draws directly on recent advances in knowledge about the nature of reading disabilities, essential components of reading instruction, and the measurement of growth and change in children's abilities. Within both preventive and remedial contexts, this research has three broad aims: 1) to determine which instructional programs have the largest immediate impact on word level reading skills and long-term impact on fluency and comprehension skills of reading disabled children; 2) to determine the individual characteristics (medical, neurological, cognitive, family background, and other behaviors) that are most strongly predictive of individual differences in both immediate and long-term response to the instructional programs we examine; and, 3) to examine the effects of the instructional programs on a broad array of cognitive skills other than reading. The use of growth curves to model change in each individual child allows not only the identification of the instructional approaches that have the largest average effect on reading, but also it enables a reliable description of the characteristics of children who respond either well or poorly to specific treatment approaches. Four multi-year studies will be carried out to accomplish these aims . Experiment 1 evaluates two approaches to the prevention of reading disabilities in a sample of 168 children selected in kindergarten because they are strongly at risk for reading failure based on phonological processing disabilities. Intervention will be provided for these children in individual tutoring sessions for two and a half years, and they will be followed until the end of fourth grade. Experiment 2 will use a sample of 90 children selected in the same way as the first study to examine the generalizability of methods used in Experiment 1 to the regular classroom. Experiment 3 will employ a sample of 60 learning disabled children from 3rd to 5th grades to examine the relative effectiveness of two programs utilizing intensive, one to one tutoring, in normalizing the alphabetic reading skills of children who have phonologically based reading disabilities. The last study utilizes 60 3rd to 5th grade reading disabled children to examine the relative effectiveness of the best approach from Experiment 3 in the context of small group instruction delivered by teachers of varying levels of experience within regular learning disabled classrooms. All subjects will undergo assessments conducted by a multi-disciplinary team that will identify the demographic, family/genetic, physical/neurological, neuropsychological, and cognitive status of each child as well as co-morbid conditions in attention and behavior.