Hick’s Law and Cognitive Load
In 1952 two psychologists, William Edmund Hick and Ray Hymn formulated Hick’s Law. They discovered that the more choices a person has the longer it takes to make the decision. Decision time correlates to the number of options we have when making a decision. In applying to design, the implication is that users take much longer to make a decision when dealing with an interface that is very busy or complicated.
Why might that be? It takes longer for the user to process the information on a busy interface because they must first examine the available options. Based on the user’s goal, choose the most suitable option — the more choices available to consider, the more time needed to analyze each choice. When the next steps are not evident, and critical information is hard to identify, users must use greater amount of deductive reasoning and intuition to come to the most appropriate conclusion.
Cognitive Load
The amount of mental resources needed to understand and interact with an interface is known as cognitive load. Just like a phone or laptop that has too many apps running or too many tabs open, the human brain can become overloaded with too much information. Users then will struggle to keep up, and tasks become more complicated and then we are overwhelmed. Our working memory buffer space has a certain number of slots to store information. If the job we are working on requires more space than available, we begin to lose data from our working memory. When tasks become more and more difficult to process, frustration and perhaps task abandonment can be the result. Frustration and task abandonment are both symptoms of a bad user experience.
Real-World Examples
One popular example of Hick’s Law is the TV remote control. As TV flat screens have become complex interfaces with multiple options for cable and app services so has the remote control. A TV remote can be complex with choices that does not just involve an on-off switch and volume control but much more. One company that realized the need for simple and compact when it involves our remote controls is Apple. They took the most basic features to operate our flat screen TVs and put them in a simple, user-friendly design. Another example of Hick’s Law involves the Google Search interface. Things are kept simple for the user and then choices gradually increase. This method of presenting options gradually improves the overall user experience.
In some cases, there could be no clear next steps or which actions are available, resulting from oversimplification. Although reducing cognitive load is a primary component of the design, oversimplification also needs some consideration. It can lead to a poor user experience as well. Users will more likely achieve their goal when they are less likely to think about what actions are necessary to reach their goal. Simplifying an interface or process increases the chance of a positive user experience. The right amount of choices for a given task leads to a quicker response time and achievement of the objective.
