Many successful elearning courses use different types of media (ie: text, images, sound, video) simultaneously to generate interest and direct the learner’s attention around the content. However, using several forms of media together can just as easily create problems that counteract learner comprehension and make your content more difficult to absorb.
Two cognitive science principles that can help you understand when different types of media may conflict with each other are the Split-Attention Effect and the Redundancy Principle.
The Split-Attention Effect
The split-attention effect is a common problem that occurs when two sources of related information are presented separately – most often in the form of a diagram or other graphic and its explanation when the two are presented on different parts of the screen. This causes the learner to have to split their attention between the two sources, which can cause them to lose some of the information from each source as they try to process both at the same time, or switch their attention between the two. The effect is worse when there is a temporal component (ie: video) when information can go by while the learner’s attention is on a different part of the screen.
The best way to design for this situation is to integrate the textual component into the graphic or video it’s explaining so that the learner doesn’t have to process the information separately, or replace the text with properly synced audio. If the different types of media are integrated properly, that will cut down on the cognitive load required from the learner.
The Redundancy Principle
When using multiple forms of media, another thing to avoid is presenting the same information in multiple different mediums. A frequently occurring example is the use of text to explain a graphic at the same time there is narration doing the same thing. Learners may try to compare the information coming from different formats, and have trouble focusing when doing so. Also, the learners’ attention tends to gravitate towards text as it requires the most effort to process, which can cause them to miss information coming from the graphics or the audio.
Ideally, if the content can be presented with graphics and audio, you can do away with text altogether. Always keep in mind the cognitive demands you are placing on the learner with the content you are presenting, and streamline as much of your elearning as possible to reduce the amount of effort needed to process and understand the information effectively.
Pathways 