Educators who want to engage their students and add sizzle to their lessons by using video clips and interview transcripts can turn to “Open Vault,” a new web site launched by Boston-based public television station WGBH. The site features video clips and interviews from WGBH programming created between 1968 and 1993, including clips of Muhammad Ali discussing his refusal to fight in Vietnam, African American students arriving at school during Boston’s court-ordered desegregation, and Robert McNamara reading from a letter sent by Nikita Khrushchev to President Kennedy during the Cuban Missile Crisis. Open Vault includes more than 500 streaming video clips and more than 1,000 interview transcripts in all. Users can search by keyword or browse by topic (arts, business, education, humanities, Massachusetts, science and technology, and social science) and can view data alphabetically by person and by series. In addition, resource management tools allow educators to annotate and tag records, create topical lists, and send information to students for further study or classroom discussion.