In spring 1994, the National Assessment of Educational Progress (NAEP) collected information on student achievement in reading, U.S. history, and geography at grades 4, 8, and 12. To provide a context for interpreting NAEP findings, the project collected background information from students, teachers, and school administrators using separate questionnaires. This publication describes the NAEP teacher background questionnaire, developed by individuals with expertise in classroom teaching, survey methodology, policy analysis, and educational research. The teacher questionnaire was given to teachers of assessed students at grades 4 and 8 only. This discussion focuses on analysis issues addressed by three types of background questions--instructional content, instructional practices, and teacher background, education, and resources--and specifies the purposes of the teacher background questions. These purposes have to do with existing instructional conditions, instructional factors by demographic subgroup, trends in instruction, relation of instruction to performance, and changes in performance in relation to trends in instruction. A matrix for conceptualizing the type, content, and uses of the teacher background questions is provided. Selected questions from the NAEP Teacher Background Questionnaire are appended. (LL)