Entry-level kindergartners in classrooms from five middle class school districts were given a test of letter identification and children who scored at or below the 30th percentile on the test were classified as "at risk" for early reading difficulties. Half of these children were randomly assigned to a project-based intervention condition where they received supplementary intervention in small groups until the end of their kindergarten year. The other half received whatever remedial services were available at their home schools and literacy skills development in both groups was tracked throughout kindergarten. All available at-risk children were again assessed at the beginning of first grade and dichotomized into a "continued-risk" group and a "no-longer-at-risk" group using a composite measure of basic word level skills. Normal reader controls were also identified using the same measure. Children in the continued-risk group received either project-based intervention (one-to-one tutoring 30 min daily) or school-based intervention throughout first grade. Intervention for project treatment children was discontinued at the end of first grade and literacy development in all groups was tracked until the end of third grade. The present study focused on literacy development in children who received only project-based kindergarten intervention or both (project-based) kindergarten and first grade intervention, relative to the normal reader controls. Of special interest was the question of whether measures of response to intervention would more effectively distinguish between continued-risk and no-longer-at-risk children than would kindergarten screening measures, measures of intelligence, or measures of reading-related cognitive abilities. Results indicated that the RTI measures more effectively and more consistently distinguished between these two groups than did the psychometric measures.