Multimedia presentations such as computer-based-training (CBT) modules are widely used in the corporate and educa-tional arenas. Programming such a presentation in a high-level language such as C++ (or even Visual Basic) involves writing code for the detailed arrangement and control of graphics, animation, sound, and user interaction. Authoring systems offer an alternative way to develop presentations or courses. The developer specifies the sequence of graphics, sound, and other events, and the authoring system gener-ates a finished program based on those specifications.
Authoring systems can use a variety of models for orga-nizing presentations. Some use a scripting language that specifies the objects to be used and the actions to be per-formed (see scripting languages). A scripting language uses many of the same features as a high-level program-ming language, including the definition of variables and the use of control structures (decision statements and loops). Programs such as the once ubiquitous Hypercard (for the Macintosh) and Asymetrix Toolbook for Windows organize presentations into segments called “cards,” with instruc-tions fleshed out in a scripting language.
As an alternative, many modern authoring systems such as Discovery Systems’ CourseBuilder use a graphical approach to organizing a presentation. The various objects (such as graphics) to be used are represented by icons, and the icons are connected with “flow lines” that describe the sequence of actions, serving the same purpose as con-trol structures in programming languages. This “iconic” type of authoring system is easiest for less experienced programmers to use and makes the creation of small pre-sentations fast and easy. Such systems may become more difficult to use for lengthy presentations (due to the num-ber of symbols and connectors involved), and speed of the finished program can be a problem. Other popular mod-els for organizing presentations include the “timeline” of Macromedia Flash, which breaks the presentation into “movies” and specifies actions for each frame, as well as providing multiple layers to facilitate animation. With the migration of many presentations to the Internet, the abil-ity of authoring systems to generate HTML (or DHTML) code is also important
Authoring systems can use a variety of models for orga-nizing presentations. Some use a scripting language that specifies the objects to be used and the actions to be per-formed (see scripting languages). A scripting language uses many of the same features as a high-level program-ming language, including the definition of variables and the use of control structures (decision statements and loops). Programs such as the once ubiquitous Hypercard (for the Macintosh) and Asymetrix Toolbook for Windows organize presentations into segments called “cards,” with instruc-tions fleshed out in a scripting language.
As an alternative, many modern authoring systems such as Discovery Systems’ CourseBuilder use a graphical approach to organizing a presentation. The various objects (such as graphics) to be used are represented by icons, and the icons are connected with “flow lines” that describe the sequence of actions, serving the same purpose as con-trol structures in programming languages. This “iconic” type of authoring system is easiest for less experienced programmers to use and makes the creation of small pre-sentations fast and easy. Such systems may become more difficult to use for lengthy presentations (due to the num-ber of symbols and connectors involved), and speed of the finished program can be a problem. Other popular mod-els for organizing presentations include the “timeline” of Macromedia Flash, which breaks the presentation into “movies” and specifies actions for each frame, as well as providing multiple layers to facilitate animation. With the migration of many presentations to the Internet, the abil-ity of authoring systems to generate HTML (or DHTML) code is also important
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