The National Gallery's collections embrace every major school of western European art from the 13th century to the present and of American art from colonial days to the present. A professor-in-residence position is filled annually by a distinguished scholar in the field of art history; graduate and postgraduate research is conducted under a fellowship program; programs for children and the general public are conducted daily; and Extension Programs produces and distributes education resources for loan throughout the world; audiovisual materials include films, slide teaching programs, videocassettes, videodiscs, and CD-ROMS.