In other presentations, such as transparencies and animation, abruptly skipping or pausing the presentation materials can be acceptable. Thus, different algorithms can be designed to efficiently handle the presentation scheduling of these streams.

Without loss of generality, let presentation P contain n synchronization points. We associate each synchronization point with START event and/or END event, as follows:

Scheduling strategies must be designed to handle delays. In this context, the E-GROUPs specified within each multimedia presentation summarizes the most critical scheduling information. The scheduler ensures that only consistent schedules will be generated by controlling the invocation order of events in the formulated E-GROUPs of each multimedia presentation. At least two parameters, maximum delay, denoted D d^max_i, and maximum skip, denoted D s^max_i, at any point of the stream, must be specified for each media stream m_i. If maintenance of good utilization is of highest interest in a particular instance, then the amount that can be skipped should be specified as a relatively small figure. If it is more important to minimize the average delay, then the delay allowed for the media stream should be set at a relatively low level. In our context, users may have different expectations for various presentations of learning materials. Thus, the choice of QoS parameters may vary in different stream presentations.

Within the given QoS parameters, any asynchrony of the presentation can be restored by compromising between skipping and pausing. Various algorithms can be designed to permit different skipping and pausing strategies for different applications. The inv ocation rules for events in E-GROUPs are as follows; assume that all START events in E-GROUP$_1$ have been invoked.