Have you ever visited a website and found you have no idea where you are or what the system is expecting you to do next? It’s not that the site isn’t designed well or doesn’t work as promised. It’s that it just doesn’t make sense to you. My school-age netizen daughters summarize this experience with a resounding "Duuhhh!" In my mind, this experience isn’t necessarily a failure of logic or navigation. The problem is more fundamental to the human experience with systems. It’s a problem of metaphor.

Metaphor is a familiar concept in literature. Merriam-Webster’s Collegiate Dictionary defines metaphor as "a figure of speech in which a word or phrase literally denoting one kind of object or idea is used in place of another to suggest a likeness or analogy between them." In Ernest Hemingway’s novel A Farewell to Arms, he uses rain as a metaphor to symbolize the pain and sadness his characters feel as they confront the horrors of war. When building systems, designers often portray the coded worlds they create using metaphor so that they are easily understood and quickly accepted by users.

So what does metaphor have to do with technology? Well, if you think of metaphor as the intuitive dimension of good user interface design you might find that your users are happier and more comfortable. Good webpage designers know how to choose aesthetically pleasing combinations of graphics, fonts and colors. Capable software engineers know how to create screens and transactions that function properly. An effective metaphor makes a site or system intuitively obvious to the new user by providing comfortable and familiar surroundings that help users quickly absorb the content of a site or adapt to the rules of a system. Take the shopping cart used in online stores, which helps ground users by providing a brick-and-mortar object for them to relate to. An ineffective metaphor makes the system more difficult and less intuitive to understand. It’s possible to design visually attractive systems that function correctly but still confuse and disappoint users.

One example of an effective metaphor from my experience involves the creation of a system for a global team of air filtration scientists at a company I used to work for. These users were already looking for a way to catalog their knowledge and exchange new ideas on a daily basis. Because of the academic nature of their work, they wanted a library for their research and reference work that team members around the world could easily access. To meet that requirement, I created a Lotus Notes library database that was customized with meta-data fields that allowed users to search and index their work in ways they were accustomed to. This new virtual library became a metaphor for the physical libraries they used in their individual sites. The group was also accustomed to regularly communicating with their scientific colleagues over the Internet. To meet this need for the internal community, I chose a Lotus Notes discussion forum that mimicked the Usenet groups the team members were familiar with. Finally, I integrated the forum and library so that they were easy to use together as a tool for daily collaboration.