There are three possible ways to search the site. First, narrow the videos by category to search for a keyword in a given discipline (e.g., find ‘Photon’ in Physics). Second, hone in on a video with specific features with a search using ‘AND’. For instance, you may want only physics videos that are short (under 3 minutes). Third, search using ‘OR’. For instance, you may want all videos that are marked ‘Chemistry’ OR ‘Introductory’. The three methods of searching are independent (you cannot combine ‘OR’ and ‘AND’).