Current educational reform in K-12 schools in this nation is much driven by the No Child Left Behind Act. One central goal of NCLB is to "bring all students (including special education children) up to grade level in reading and math, to close the achievement gap and to hold schools accountable for results"(ed.gov). Varied innovative…

This article examines a premise underlying teacher accountability policies, namely, that annual student learning gains can be attributed to individual teachers. After analyzing data collected in fourth- and fifth-grade reading and mathematics classes in 18 schools, the authors identify forms of instructional design that rely on multiple teachers.…