Development of text materials and visual materials relies upon theories related to visual perception, reading and human information processing as well as theories of learning. Audiovisual Technologies Audiovisual instruction is most obviously characterized by the use of hardware in the teaching process, that is, using mechanical or electronic machines to present auditory and visual messages. There is an increasing overlap of AV Technologies with Computer-based Technologies. For example, a video is an audiovisual technology. However, when video information is available on a videodisc, it becomes randomly accessible and may demonstrate most of the characteristics of computer-based or integrated technologies.
Information is stored electronically in the form of digital data rather than as print or visuals.
Integrated Technologies Integrated technologies are ways to produce and deliver materials which encompass several forms of media under the control of a computer. An example of an integrated system would be a computer which has a hypermedia lesson running under an authoring system such as HyperCard or Toolbook . As controlled by the learner's interaction with the computer keyboard and monitor, the computer would access these various resources and deliver the output to the computer screen. The learner doesn't have to be concerned about the delivery of the resources, but can concentrate on the content of the lesson. This is the oldest of the domains because regular use of AV materials predates even concern for production of instructional media.