Hick–Hyman Law and Design

Psychologists William Edmund Hick and Ray Hyman define “the time it takes for a person to make a decision as a result of the possible choices he or she has” in the Hick–Hyman Law.That is, increasing the number of choices will increase the decision time logarithmically.

This means that people subdivide their total collection of choices into categories, eliminating about half of the remaining choices at each step, rather than considering each and every choice one-by-one, requiring linear time.

So what does this have to do with design? Everything! We live at the intersection of the Information Age and the Experience Economy. We have more data now then ever before for us to sort through to make decisions. We see this in our everyday life – when we try to decide what cereal we should buy from the shelves and shelves of choices at a store, or what item you need to find from the multiple menus of a website or kiosk. This is the Hick-Hyman law at work.

That store can help us by providing signs for categorizations. The same is true for the information design of the website or kiosk. Especially when taking in account Fitts’s Law, one large menu is more time-efficient than several small sub-menus supporting the same choices, even if we ignore the time overhead of moving among sub-menus.

The site from Keurig.com (circa 2013) features a well-structured mega-menu that does not require excessive motor effort to use.

keurig.com mega menus work better than thin drop downs

Designing an experience with too many features can be distracting and overwhelming – causing cognitive load.  When we have too many elements in our experience, we reduce the value of the primary content and force a harder decision making process on our customers. The process of eliminating any distracting should be carried on throughout the design process. The old rule of “remove half, than half again” applies.

So that is how we make sense of the large data sets we have today. We have all had experiences that lack structure, spacing and consistency – be it in the grocery store isle, website, or on our mobile device. The content gets lost, and we give up entirely when we aren’t given the tools to make confident decisions. Building a great experience has a lot to do with how we empower our decision-making process following the Hick-Hyman law.