Journals, or diaries, are logs that document emotions, events, ideas, and information. They are an effective method of record keeping during various stages of research. This entry outlines five types of journals researchers can keep through the course of their research and details how to use them in each context: (1) observation journals, (2) methodological journals, (3) theoretical journals, (4) analytical journals, and (5) personal journals. This entry also includes information on journals and diaries kept by research participants at the request of researchers.