Filtering refers to the process of selecting or sorting out relevant information from a larger pool of data. In the context of research, filtering involves applying specific criteria or algorithms to narrow down the available sources to those that are most likely to be relevant to a particular topic or question. This can help researchers save time and resources by focusing on the most pertinent information and excluding material that is less useful or reliable. Filtering can be done using a variety of methods, such as keyword searches, citation analysis, peer review, and manual screening.