“The time it takes to make a decision increases as the number of alternatives increases”
Designers can improve the efficiency of a design by understanding the implications of Hicks law. Hick’s law, also known as the Hick–Hyman Law is named after after the British and American psychologists William Hick and Ray Hyman. The law describes the time it takes for a person to make a decision as a result of the possible choices he or she has: increasing the number of choices will increase the decision time. The law is used to make a prediction as to how long it will take for people to make a decision when presented with multiple choices.
For example, in a situation where response time is critical such as an airline pilot, the greater number of choices available such as buttons to press in response to an alarm will increase the time it takes to make that decision. In these situations systems need to be designed to allow the user to make quick decisions.
It is also important for a web designer to consider Hicks law when creating a shopping cart. If a user was presented with the entire buying process involved in making a purchase on a site such as Amazon.com or Lego.com, many would give up and not follow through with a purchase. These sites will break up the purchasing experience by breaking down the process by prompting users to firstly click to add to a cart, then asking to register their e-mail and create a password. They will then give buyers another screen with payment details, then another which collects delivery information and so on. By reducing the number of options on screen, the payment process becomes more user friendly, and it’s more likely that the user will reach the end of the process rather than abandon the cart.
It is also important to know when not to use Hick’s Law. The law does not apply to complex decision making such as when complex reading, searching, deliberation or problem solving is required. In these cases, Hick’s Law won’t be able to predict the time to make a decision. An example of this is in selecting a meal from a restaurant menu. This task generally does not involve time pressures and involves an amount of reading and possibly discussion before deciding on an option.
These type of choices are complex. Users need to consider and weight many options before making the final decision. In these cases, Hick’s Law prediction will fail. It only applies to simple quick decisions in appropriate context.