Authors also must support user-directed access. Advantages to authors include a wide audience, the opportunity for effective communication and prestige. CD-ROMs are less expensive to publish than books. Electronic seminars are not limited by attendance. An author can include sound, animation and digital video to improve communication of material.
Users are more enthusiastic about multimedia than other types of publication.
Disadvantages to authors include great time and effort, rapid obsolescence and intellectual property issues. Educational multimedia software is very time-consuming to produce. It is estimated that 1,000 hours of author's time is required for each hour of user's time. Most lectures with slides require about five hours of author's time for each hour of lecture. Timelessness is very hard to achieve in digital medium.