The use of computers to build diagnostic inferences is presented in two contexts: (1) closed world, exemplified by the space shuttle launch monitoring system; and (2) open world, represented by computerized diagnostic testing of reading comprehension. The analysis shows that the closed world provides a substantially cleaner environment within…

Included in this thorough overview of the probable future developments in videodisc technology and its role as an educational medium are (1) a review of current educational technology literature on videodiscs, which summarizes a U.S. Navy Delphi Study of videodisc technology use through 1986, discusses a National Institute of Education (NIE) study…