Human based systems (teacher, instructor, tutor, role-plays, group activities, field trips)
Print based systems (books, manuals, workbooks, job aids, and handouts)
Visual based system (books, job aids, charts, graphs, maps, figures, transparencies, slides)
Audio-visual based systems (video, film, slide-tape programs, live television)
Computer based systems (Computer based instruction, computer-based interactive video, hypertext)