This randomized controlled study investigated the efficacy of a Tier 1 intervention--schema-based instruction--designed to help students with and without mathematics difficulties (MD) develop proportional reasoning. Twenty seventh-grade teachers/classrooms were randomly assigned to a treatment condition (schema-based instruction) or control…

This study used a statewide longitudinal sample to examine mathematics achievement gaps and growth in students with and without disabilities and to examine the impact of different methods of determining disability group membership on achievement gaps and growth. When disability status was determined on the basis of special education placement each…