The Split Attention Principle in Multimedia Learning
Ayres and Sweller talk about how to transfer large amounts of information without ‘overloading’ the user. The overloading phenomenon comes from their explanation of ‘cognitive load theory’ which basically says that after a certain point, the user becomes overwhelmed with too much information, or sensory overload that they cannot further information.
Of course we as designers are looking to transfer as much information to the user in as little time as possible so as to fully enable understanding of our application/data. The trick is to look for the optimum point at which the information is a manageable quantity and the user is not so overwhelmed as to completely shutdown. There is also the ‘split attention principle’ which discourages a design where a user’s attention is too divided amongst multiple area. Sometimes we want this to happen, it is easier for a user to absorb information on a subconscious level from many different sources (for e.g. sight and sound working together to create a complete visualization) but the goal is to create the harmonious integration of these sources and their level of information output.
POET: The Psychology of Everyday Things
Norman leads us through the concept of how everything has a design, a concept and a character. No object is too simple or mundane to have a design and functionality, from a doorknob to a refrigerator. To illustrate this, Norman uses the example of the refrigerator thermostat. Before anything can happen, the conceptual model for the working of the thermostat must be created. Then there is the user’s model, which is how the user expects the design to work. The correct transfer of conceptual model to match the user’s model happens through the system image. If the system image cannot successfully do this, the discord between the two mental models will cause a failure of the application, or an incorrect understanding of how it works.
Norman also talks about the importance of visibility and the large role it plays in helping users understand the system. Often it is the choice of what NOT to make visible that is a crucial part of making the design easy to understand. Revealing too much can also introduce extraneous thinking and confuse the functionality of features.
Directing the visual path of a user is crucial in leading them through a visualization and giving the the maximum chance of understanding it correctly. There are many factors that influence the visual path, these include color, orientation, patterns, shapes, depth of field, motion and gloss. Each one of these factors can be tweaked to make certain objects stand out and hence create a series of visual stimuli, dictating how you want the user to progress through the visualization.