This article reviews a wide range of research literature and makes the argument that the existence of "cognitive load" is not necessarily a bad thing in the design of educational multimedia-as opposed to the design of software applications! tools. It also presents a model of educational multimedia learning that delineates different types of cognitive load induced by multimedia and evaluates their differential contributions-or, alternatively, hindrances-to successful learning. Suggested design solutions and techniques are offered based on empirical data, as well as logical outcomes of the proposed model.
The model presented in this article integrates a myriad of research regarding--or indirectly related to-designing educational multimedia for optimal user comprehension and learning. This model is squarely based on theories/ideas/models running through the research literature in cognitive psychology, but does not hesitate to borrow from other lines of research--for example, in educational psychology, cognitive science, human-computer interaction, human factors, and so forth-when and where considered productive.
The author believes one of the reasons the development of such a model is so complicated has to do with the existence of parallel-though not necessarily independent-design considerations. Thus, it appears it is necessary to construct multimedia to fall within different constraints along different dimensions that are acting both individually and in concert with one another.
Simplifying the model to contain only a few critical dimensions requires a great deal of integration and condensation of existing studies and their findings, but can yield some rather complex-though reasonably functional-design dimensions.
Three broad factors or dimensions to consider when designing educational multimedia have been distinguished:
* regulating total cognitive load;
* regulating relative dominance of load types; and
* maximizing concurrent activation (i.e., simultaneous conscious attention) of relevant features of incoming information and (at the same time) relevant prior knowledge.
REGULATING TOTAL COGNITIVE LOAD
A commonly accepted principle in cognitive psychology and other social science disciplines is that working memory capacity-and attention-is fairly limited in humans, and when this limited capacity is overwhelmed, decreased levels of cognitive performance result (Sweller, 1988). The time-tested finding that working memory can contain or maintain around seven "chunks" of information, plus or minus two (Miller, 1956) is accepted, where these chunks might be thought of as schemata and where a more greatly articulated or developed schema can contain a greater amount of information than a lesser articulated or developed schema (Chi, 1988; Simon, 1974).
A common theme in software and multimedia design is minimizing cognitive load for the purposes of usability and learn-ability. The thinking is that keeping cognitive load low allows the user to interact with the software or multimedia without becoming overwhelmed or confused by the options or information being presented. When a software application imposes a large cognitive load on the user, it becomes difficult for the user to learn and/or use the application.
When a piece of software is an application or tool, this thinking makes sense because the application or tool is only a means for interacting with and/or creating content that can stand on its own independently of the application or tool. A user learns the application or tool to allow them interact with it and produce the actual content they are ultimately interested in. Since the capacity of working memory is limited (Miller, 1956), any load imposed by the tool reduces the amount of working memory capacity available for content-related thinking and processing.
In contrast to software applications and tools, educational multimedia actually contains content the user is interested in learning. …