Designing with assumptions

Published on 18^th February 2010 in Design, Usability, tagged ethnography.

Last week I conducted my first ethnographic study as part of a university group project. Our task was to go into people’s homes and learn about how they share and store photos, whether that’s in digital or physical form. While other members of my group surveyed young couples and families, I went and talked to two retired couples.

This exercise proved to be interesting not only because it was the first of its type that I’d done, but because it exposed the vulnerabilities of designing with assumptions when such a wide range of people are the target audience.

Dealing with the ‘obvious’

During one of my studies, I asked someone to walk me through the process of importing a photo from a camera to their computer, as they normally would. Of the entire process, the following screen caused by far the most problems:

At first glance, this looks fairly straightforward; you choose a name and pick a folder, then click “Next”. However, what may be obvious for some of us might not be for everyone else.

When I asked the participant about this screen, he mentioned that he didn’t know what the “\” symbol meant. For people who have grown up with computers, this is immediately recognisable as a folder separator. With this knowledge, the assorted letters in the drop-down are a clear file hierarchy, but without it, they’re simply a jumble of words. If you didn’t know what a backslash represented, which would you pick?

Designing with assumptions

So how can you design around problems like this? First of all, you need to know your audience. In this instance, the target audience includes anyone that takes photos and uses a computer, so it’s extremely broad. On the other hand, you might be designing an interface for a very narrow audience, such as medical professionals.

Understanding who will be using your product is essential because the number of assumptions you can rely on is inversely proportional to the size of your audience. In other words, the more varied your audience is, the fewer assumptions can be made.

If you’re designing something with a tightly controlled user group like a commercial airliner, you can almost guarantee that they will know certain things. However, if you’re working on a screen like the one above, you have to greatly reduce the user’s assumed knowledge.

To conclude

Almost every task we’re faced with in everyday life relies on using assumptions that we’ve learned. When you use a new toaster for the first time, you assume that by pushing the lever down, it will toast bread.

This is obvious, but what if you didn’t know that? Are there affordances and clues that allow unfamiliar users to operate it? How would you learn about that common, assumed knowledge for the first time? Asking similar questions about your user interfaces often pays dividends.