It is de facto impossible to work on two similar tasks at the same time. This is mainly due to our cognitive resources, i.e. our ability to mentally process sensory impressions. These are limited, so our brain uses filtering methods to focus on the relevant and block out the irrelevant. One example of this is the cocktail party effect: our ability to block out the conversations around us in crowds and listen to the person we are talking to at the same time.
However, this so-called selective attention only affects the respective senses. We are perfectly capable of listening to our conversation partner and observing the other party guests at the same time. So is multitasking possible after all?
This is where the theory of multiple resources first put forward by Christopher D. Wickens in 1980 comes into play. This theory states that multitasking is possible under certain circumstances if both tasks require different cognitive resources. It divides human cognitive resources into the categories of processing level, sensory modality and encoding.
In the processing phase, a distinction is made between the phase of perception and cognition and the phase of selecting and executing a reaction. This means that you can perform two tasks quite well at the same time if one consists of perception or mental processing and the other consists of selecting or executing a behavioural response.
The subdivision according to sensory modality means, for example, that you can take in information visually and auditorily at the same time.
Encoding refers to the way in which information is processed and stored. This can be both spatial and verbal. If two tasks use the same type of encoding, it can be difficult to complete them simultaneously. With different types of encoding, more effective simultaneous execution is possible.
This model allows us to assess whether cognitive overload and possible failure are likely in a dual task. At M&M, we can also design interfaces and interaction concepts in such a way that overloading becomes less likely.
At M&M, we utilise this knowledge as early as the requirements process and when deriving interaction concepts. For example, if a user's task is to monitor parameters and end a process by pressing a button, it is advisable to display these graphically in the form of tachometers, diagrams or infographics wherever possible. Why? This should be done because the termination of the process requires a manual-spatial reaction and the encoding, in terms of the resource model, should therefore also be possible spatially.
Conclusion: Wickens' resource model offers considerable potential in software development, especially in the design of user-friendly interfaces. It enables the design of interaction concepts that can help to optimally support users in their activities.
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