Deciding on a topic can be one of the hardest parts of the research experience. As you explore areas of interest to you, it's important to discover what other scholars have already written on the subject, and find new areas of inquiry to pursue.
Subject encyclopedias, bibliographies, and test searching in subject databases can help you get up to speed on what scholars have been working on, get ideas on new directions to follow, and get a list of readings you may want to consult and engage with.
Video tutorial courtesy of the librarians at North Carolina State University.