Memory: Recognition versus Recall

One of the best known findings in memory research is that we can recognize things much more easily and accurately than we can recall them. If you were given a list of 15 words to remember, you would remember more of the words correctly by recognizing them from a larger list of words than if you tried to simply recall them and write them out on paper. The common experience of knowing that we've met someone without remembering their name is the same phenomenon. We're simply much better at recognizing (e.g., a face) than recalling (e.g., a name).

The advantage of recognition over recall has obvious implications for user interface design. In fact, graphical user interfaces are typically easier for people to learn and use today then they were 20 years ago, largely because they exploit the recognition advantage. Today's GUIs employ a wide array of menus, listboxes, dropdowns, options, and icons. Instead of requiring users to recall a command name or a particular combination of keystrokes (remember DOS and Unix?), users need only scan through a dropdown list until they recognize the name, command, or icon of interest to them.

Psychologist and human factors guru Don Norman has since reframed the recognition versus recall distinction in terms of "knowledge in the world" versus "knowledge in the head". It's easier for us to remember by recognizing what the world shows us than by recalling it from our heads.

Unfortunately, user interface designs fail to exploit the phenomenon more fully. Too often, user interface screens provide little support in helping users remember how to perform an operation or complete a task. Designers tend toward organizing screens by grouping user interface elements by their architectural function rather than by task flow. The arrows in the figure below show the sequence of user interface controls that users needed to use to perform the most common task for a screen. The design forced users to recall the sequence (knowledge from their heads) rather than recognize the required sequence by having the order of controls mimic the task steps (knowledge in the world).