The chapter describes an ongoing project aimed at understanding the impact of instruction on children’s early literacy growth. Derived from direct observations of classroom instruction, findings revealed that the most effective instruction depends on the initial skill levels of the child. These child X instruction interactions imply that efforts to improve children’s literacy skills will be greatly enhanced by a focus on tailoring instruction to each child’s profile of strengths and weaknesses. An intervention is described that attempts to provide such individualized instruction combining a small-group focus with computer support that specifies the amounts and types of instruction each child needs to advance. Findings from the intervention demonstrated greater reading growth for the individualized instruction group over a control group. Further, the more the instruction matched recommended amounts and types for each child, the more children grew. Theoretical and practical implications are discussed.