Response to Ayres and Sweller, "The Split Attention Principle in Multimedia Learning"
Paul Ayres and John Sweller apply the split-attention principle to the design of multimedia instruction, asserting that it is "important to avoid formats that require learners to split their attention between, and mentally integrate, multiple sources of information" (135). This assertion is based on the theory of cognitive load, which refers to the amount of information the brain is able to process at any given point in time. The greater the number of sources of information in multimedia design, the higher the cognitive load required to understand it. An "extraneous" cognitive load, as Ayres and Sweller diagnose it, hinders the learning process by requiring users to split their attention and "mentally integrate the multiple sources of information" (135). As such, it is often necessary for the designer of a piece of multimedia instruction to do as much as possible to present the multiple sources of information in an integrated format.
With practice and expertise, the brain can be taught to expedite the process of piecing together disparate sources of information without need for additional visual aids, such as the algebra student being able to readily identify angle measures of a given shape. But for the novice learner, "substantial cognitive resources will need to be devoted to splitting attention between the disparate sources of information and mentally integrating them" (137). As a way to lessen the cognitive load, then, designers can employ visual cues or "referrents" that help integrate multiple sources of information. Other ways to help learners piece together multiple information sources is what Ayers and Sweller call the "dual mode" of multimedia design, which refers to the use of two different sensory cues, usually sight and sound, to lessen the cognitive load.
Response to Donald Norman, The Design of Everyday Things
In The Design of Everyday Things, Donald Norman looks at the design of familiar items to explain how to construct effective visual aids. At the heart of all user-friendly designs, Norman asserts, lies two fundamental components: a good "conceptual model" and a logical "visible structure" (13). An effective conceptual model should allow us to predict the outcome of our actions by explaining how an item works in a theoretical manner. Ideally, conceptual models should be as simple as possible, but the presiding imperative must always be accuracy and clarity of explanation. The item itself must also employ a logical visual structure, including the intuitive use of what Norman calls affordances, constraints and mappings. It should be clear to the eye from visual cues what an item can do (its affordances), what it can't do (its constraints) and how to connect the various parts together to perform an operation (mapping).
Response to Wolfe, Visual Search
Jeremy M. Wolfe lays out the basic principles of visual search, shedding light on the often unconscious ways our brains process sensory information based upon certain visual cues. Perhaps most importantly, Wolfe defines the basic structural features of visual search, including color, orientation, motion, size and scale. While many such basic features may appear obvious, Wolfe goes a step further in pointing out the various psychological factors that can come into play in our processing of visual information. For example, in keeping with Plato's idea of forms, Wolfe asserts that an object is more than just the sum of its parts; it is an object in its own right. As soon as attention arrives, Wolfe contends, "an object is not seen as collections of features. It is an object having certain featural attributes." An object carries with it certain mental associations that change the way users perceive it.