Choice is a strange thing. The decisions we make shape everything we do, everything we are.
We deem choice a luxury. Liberating people with added choice was the running theme of the last century. Giving women the choice to vote. Removing racial segregations, opening up a plethora of choices for minorities across the world.
It seems only logical then to presume that offering an increased amount of choice is a great thing. Liberating people, allowing them to choose exactly what they want.
You’d be wrong.
Hick’s law, named after British psychologist William Edmund Hick, describes the time it takes for a person to make a decision. This decision time is based on the possible choices he or she has. The law states that by increasing the number of choices, the decision time will also increase logarithmically.
Hick’s law considers the amount of information stored by a subject, and how long it takes to process this information to come to a decision. The more information, the longer it takes to process. This part of the law is known at the rate of gain of information
The equation is as follows:
Where, H is the average time taken to make a choice. n represents the number of choices, all with equal probability.
The Jam Example
A classic example of Hick’s Law in action is a study testing the effects of jam options in a busy supermarket. The study used two different jam tasting displays. One with 24 different jams, and the other with only six.
Results showed that with the 24 option display, 60% of people passing tried the jam with 3% of them purchasing. With the 6 jam display, a lesser 40% of people stopped but almost 30% purchased (Source).
When faced with 24 different jams, the overwhelming amount of choice made it difficult to select one in particular. Think of the jams as a spectrum of colour. By providing all the colours in that spectrum, how do you choose that single shade of grey? How do you justify a decision when faced with a negligible difference?
With only 6 colours in that spectrum, differences are starker, and a firm decision easier to make. That grey area is gone. In the jam example, taste is easier to distinguish, and thus it is easier to determine which is best.
Hick’s Law in Web Design
So how exactly does this law apply to Web Design? How can we use it to fine-tune user experiences?
Websites aren’t quite supermarkets filled with jam, but your standard site isn’t too far off. Hick’s Law is proportional to the cost-benefit principle. The more options a user has to pick from — be it navigation, products or images to look at — the more energy it takes to make a decision. In the end, the energy required to make the decision becomes so large the benefit of making it doesn’t seem worthwhile.
The Marriage of Cost-Benefit, and Hick’s Law
A great example of these factors combined is ‘form fatigue’.
A visitor is browsing your site, and is suddenly confronted by a survey about their experience. The user is a kind hearted soul, so begins filling out the form. Faced with 10 multiple-choice questions, he begins:
With 8 choices for each question our user must deliberate each answer. Which one is appropriate to them? (Too much choice – Hick’s Law). After 3 or 4 of these, considering which of the 8 choices is relevant, our user gives up. He returns to browsing the site. Why? How does the survey benefit him. Is it worth his time and effort? (Cost-Benefit Principle).
On the web, Hick’s Law tells us to keep options to a minimum. This applies to everything. Content on the page, navigational elements, images, product choice, etc… By removing unessential choice, we reduce the amount of unnecessary decisions that have to be made. This speeds up the user’s interactions, reducing the time it takes to get those conversions. Reducing the chance users will become frustrated, give up and leave.
Choice puts rabbits in headlights. By offering clear paths we can reduce navigation time, ease user experience, and reduce drop-offs.
Never take visitors for granted. Treat the time they spend on your website at a premium. Use it wisely.
Curate content into appropriate categories. Clothing sites regularly split Male/Female, with a further breakdown of categories beneath. Reduce overall choice into manageable chunks.
This works for navigation too. Remove long navigational lists. Better to have 3 branches with a further 3 sub-branches, than a long list of 9 places to go.
Effective use of filter and search options. By using these, large streams of content can be reduced into manageable, relevant lists.