In the spring of 2008, the Center on Education Policy (CEP) continued its ongoing research on the impact of the No Child Left Behind Act (NCLB) by conducting case studies of six schools in Illinois to learn more about the effects of NCLB and related state accountability policies on curriculum, instruction, and student achievement. The schools studied used a variety of instructional practices and included a mix of urban, suburban, and rural schools, as well as elementary and high schools. Interviews were conducted with school administrators, teachers, students, and parents, as well as formal classroom observations that documented the time spent on various types of instructional practices and teacher-student interactions. Reported findings include: (1) Lack of alignment between the high school exam and state standards; (2) Use of varied test preparation techniques; (3) Use of instructional time in elementary classes differs by subject; (4) Difference in use of classroom time in higher- and lower-achieving schools; (4) Curriculum and instruction decisions are driven by data from state and other diagnostic tests; (5) Importance of strong parental involvement; and (6) Concern about what is viewed as a late decision by state officials to discontinue use of an alternative test for English language learners. Two appendixes are included: (1) Additional Information about Study Interviews; and (2) Classroom Observation Instrument. (Contains 3 footnotes, 2 figures, and 1 table.)