Using the Wickens’ Model When Designing UX

Human cognition is an incredibly complex task that to this day is not completely understood.

When designing a product or service, it’s difficult to keep in mind the complex processing that humans undergo as they encounter, not just your system, but also the world around them as they use the system.

This is where models come in.

The Wickens’ Model for information processing allows you to have a simplified idea of the phases and steps humans undergo when processing information. It allows you to consider how humans work, as they comprehend the world around them.

 

Why Would I Use a Model?

As you are coming up with your initial concepts, you can use this model to get an idea of the different parts of human cognition that your design will need to support.

Also, knowledge of the parts of this model can be used to justify design decisions when you are unsure of which approach you should take.

The Wickens’ Model Explained

Perception

The model begins with sensory stimuli entering the short-term sensory store. This is the raw data from the world around us; this data doesn’t mean anything yet. We just collect that there was a loud noise and nothing else.

When the raw data enters the perception phase is when we start to give that data some meaning. Was that loud noise a balloon popping or a gun firing? In the Wickens’ Model, this meaning comes from activating our long-term memory as well as our working memory. It’s here that our prior experience, emotional state, and value system shapes our interpretation.

Some questions to ask about your design in this phase are:

• Are important stimuli signals strong enough?
• Are you overloading the user with unnecessary distractions?
• Is this stimulus likely to be perceived incorrectly? Is it too similar to another stimulus?

Attention

It’s in the perception phase that we start to use some of our attention resources. In this model, humans only have so much attention resources to devote to various events. These limited resources force us to only attend to specific stimuli that seem most important. When we decide that the loud noise was the sound of a gun firing, we might devote all our attention to this stimulus and ignore the stimulus of a gentle breeze.

Two types of attention to be particularly aware of is divided attention (such as talking on a cell phone and driving) and sustained attention (such as watching radar). Humans are not very good at either. Limit divided and sustained attention as much as you can.

Some questions to ask about your design in this phase are:

• Is your user able to attend to all the information needed?
• Is there any way you can limit the amount of attention needed?
• Is your user able to ignore all unrelated stimuli?

Long-Term Memory and Working Memory

The long-term memory and the working memory interact with both the perception and the decision and response selection phase. Long-Term Memory is slower to access but is effectively unlimited. Working memory is fast, but easily forgotten and limited.

These two phases interact with each other closely, with information from long-term memory being brought to working memory for consideration.

Decision and Response Selection

The decision and response selection phase is where we decide what to do about our perception. This isn’t a long drawn out process. Humans don’t have unlimited time and resources, they must approximate.

Some tasks are easier and the situation allows humans to arrive at an answer that is best according to the laws of probability. Most of the time, though, humans are looking for a decision that is “good enough” which allows us to operate more efficiently. It is likely better to find the “good enough” decision of diving to the ground at the sound of a gunshot than taking the time to evaluate all the pros and cons of your possible choices.

This phase also interacts with the working memory and long-term memory to consult prior experience and use an appropriate heuristic to come to a decision.

Some questions to ask about your design in this phase are:

• Have users been prepared with a similar situation to allow them to come to the right decision?
• If this problem is more complex, are there some decision aids that you can provide the user with?
• Are there any time restrictions that limit users ability to come to a good answer?

Response Execution

Response Execution is the stage where you preform the actions that you decided upon in the last phase. It is in this phase that you actually complete that dive to the floor in response to the gunshot.

There is really only one big question to ask at this phase:

• Is the user physically able to complete the action?

Feedback Loop

It doesn’t all stop with your decision being executed. You are constantly being barraged with new stimuli and after executing a response you might get a whole new selection of stimuli related to your action.

After you dive to the floor, you could get the stimuli of new sounds and sights that you perceive to be laughter and the remains of a popped balloon. You might conclude from this that it was not a gunshot that you had heard. Your response might be to stand back up and get embarrassed.

Limitations of Wickens’ Model

While this model allows you to break up a complex process into finer detail, it is not accurate representation of how humans actually function.

This model is an oversimplification of the process that humans go through. In addition, it is also out-dated based on recent research and should not be taken as an accrete representation of reality.

TL;DR

The Wickens Model is a very useful tool to use when designing the product UX. It enables you to break down the human information process and consider all the different phases and how this might affect your design.

However, it should be used with caution. It is not a replacement for involving actual users to research and test your ideas and products. The model simplifies the process and no matter how well you use it, you can never predict completely what will actually happen.