A research reviews is a written summary of journal articles, books, and other documents that describes and critiques the past and current state of information about a topic, organizes the literature into sub-topics, and documents a need for a study. In the most rigorous form of research, investigators base this review on research reported in journal articles. A good review, however, might also contain other information drawn from conference papers, books, school reports, and government documents. Regardless of the sources of information, individuals conduct literature reviews to learn about topics, and all researchers review the literature as a step in the research process.