The Tennessee Value-Added Assessment System (TVAAS) has for several years used the largest longitudinally merged database of student achievement data in the USA. to generate estimates of school system, school, and teacher effects on indicators of student learning in a number of subjects, including reading comprehension. A Learning Information System (LIS) (not to be confused with an Integrated Learning System) is a formative, curriculum based, criterion referenced assessment delivered and scored by computer, which provides detailed feedback in different forms for different stakeholders. The Accelerated Reader (AR) LIS for reading comprehension of real ("trade") books captures the data for each student on the length and difficulty of each book, and the student's percent correct response on the assessment. It aims to help teachers promote and manage effective reading practice. AR data on 62,739 students from grades 2 to 8 in Tennessee schools was merged with the TVAAS teacher effects database, and relations...