Instructional Design Consequences of an Analogy between Evolution by Natural Selection and Human Cognitive Architecture

Evolution by natural selection may be characterized as a system in which a large store of genetic information will persist indefinitely while it remains coordinated with its environment but will continuously produce small random variations that are tested for environmental effectiveness. In any environment, effective variations will persist while ineffective variations will disappear. Similarly, human cognitive architecture includes a large store of information held in long-term memory that coordinates our cognitive activities. A very limited working memory tests the effectiveness of small variations to long-term memory with effective variations altering long-term memory while ineffective variations are lost. Both an existing genetic code and information in long-term memory provide a central executive that guides behaviour. Such a central executive is unavailable when an environment alters or when working memory must be used to deal with novel information. A major function of instructional design is to provide the otherwise missing structure of a central executive when dealing with novel information and to reduce that structural support as knowledge accumulates in longterm memory. Cognitive load theory both provides instructional design principles that would be difficult to devise without its particular view of human cognitive architecture and throws further light on that architecture. Instructional design issues and human cognitive architecture are inseparably intertwined. Not only is no useable science of instruction feasible without knowledge of human cognitive structures, but instructional design issues can impact heavily on the development of our knowledge of cognitive structures. Knowing how students learn and solve problems informs us how we should organise their learning environment and without such knowledge, the effectiveness of instructional designs is likely to be random. Equally, discovering that some instructional designs are superior to others can provide insights into human cognitive architecture that may otherwise be difficult to achieve. Cognitive load theory, with its close links between human cognitive architecture and instructional design, provides an example of the advantages of linking the two areas. The theory has used our knowledge of human cognitive architecture to generate a large number of instructional designs, some of which are unlikely to have been mapped without our knowledge of cognitive structures. More recently, the theory has begun to provide insights