This article features FAST-R, or Formative Assessments of Student Thinking in Reading, a new assessment tool that measures critical-reading skills. FAST-R was developed by the the nonprofit Boston Plan for Excellence (BPE), a local education foundation, to provide teachers with information about what students are thinking when they try to find…

Formative assessments--assessments that measure what students do and do not know, so that teachers can modify their instruction accordingly--have been widely hailed as a potential vehicle for improving student achievement. Yet little solid research evidence exists about their effectiveness, especially in reform-rich school districts. This study…