Image showing a user-friendly, intuitive interface.

Psychology in web experience - minimising the cognitive load

20.06.14

Good design reduces the cognitive load of the website as much as possible, so that the user can browse effortlessly.

Cognitive psychology in User Experience design

Psychology offers valuable concepts which can be applied to the way we think about designing an experience. If we keep in mind how our users think, we can create designs which support them unnoticeably - for instance if we minimise the amount of mental processing capacity which they have to use.

Sensations originate from the “lizard brain”, which accounts for the primitive feelings most animals have. Combined with cognitive thoughts, those sensations lead to emotions. User Experience design should trigger exactly this part of the brain by pairing it with a thought which works in our favour, as Erik Flowers explains.

Cognitive load - the user’s processing power

In psychology, cognitive load describes the mental effort required to learn new information. In UX design, the cognitive load is the amount of mental processing power needed to use a website or application. When the amount of information coming in exceeds the user’s ability to process it, the overall performance suffers. The cognitive load is too high. We can’t change the actual processing power of our users. What we can do is get to know their limits, and minimise their processing efforts.

Minimising the cognitive load

There are three types of cognitive loads:

  1. Intrinsic cognitive load is the energy needed to absorb new information while keeping track of the user’s personal goal.

  2. Extraneous cognitive load is anything taking up mental resources without helping the user to understand the content, for instance colours, fonts or sizes, which don’t convey unique meaning.

  3. Germane cognitive load is a concept which was first described in 1998. It’s the load used to construct and process schemas. This is particularly interesting for areas such as teaching, but it does not really affect UX design.

The part that we can tackle is the extraneous load, which we should minimise as much as possible.

Provide short-term memory support. Short term memory stores information for about 20 to 30 seconds. Miller’s Law argues that the number of objects which a human brain in short-term memory is 7 ± 2. Support the users and display information which they would have to store in their short-term memory. For instance, make a visited link differ from a non-visited one.

Use recognition rather than recall. Humans are better at recognising things than they are at remembering them. Moreover, recognition requires less processing in the human brain than recalling, so the risk of error or failure is reduced. We can apply this by for instance using pictures, which the user will quickly associate with an action or information.

Avoid visual clutter. A website should be simple. Avoid using five different types of typography or meaningless pictures – if you use something, you should be able to explain why. Don’t try to create the “wow” effect, go gor the “of course” design, the design which convinces by being invisible.

Make it simple. Beyond the visual simplicity, aim for content simplicity. All essential information should be on the same page as the call to action button. Don’t ask the user to go back and forth to retrieve all information needed to make a choice.

Know the mental model of your users. A mental model is the users intuitive knowledge of how something is supposed to work based on experience. Using layouts and models which your users already encountered in the past, you reduce the energy they need when browsing your website.

If the users do not notice the design, they are also not using unnecessary processing power on it: Noticing nothing means effortless browsing.