There are two categories of distance education delivery systems, synchronous and asynchronous. Synchronous instruction requires the simultaneous participation of all students and instructors. Asynchronous instruction does not require the simultaneous participation of all students and instructors. Students do not need to be gathered together in the same location at the same time. Rather, students may choose their own instructional time frame and gather learning materials according to their schedules.
Asynchronous instruction is more flexible than synchronous instruction.
Moreover, in the case of telecommunications such as email, asynchronous instruction allows and even may encourage community development. Forms of asynchronous delivery include email, listservs, audiocassette courses, videotaped courses, correspondence courses, and WWW-based courses. A disadvantage to consider with email-based interaction is the considerable written exchange, which could really pile up. Distributed Learning Services, Towson University, Towson, Maryland. Distance Learning Facts Research studies have been quite consistent in finding that distance learning classrooms report similar effectiveness results as reported under traditional instruction methods.