Hallway usability testing: How much of the UI do you actually make functional?

Question

When doing hallway usability tests do most of you make your apps fully or near fully functional? Or do you just make sure the links or flow chain correctly? Or do you just draw on paper and go with that?

I'm would like to test early on a prototype and am trying to find a good balance. But at the same time am worried that some non functional parts might actually not give representative results.

Thanks.

Answer 1

Usability tests, hallway or otherwise, only need the functionality that you need to test. In most usability tests, you should go in with specific design questions to answer and develop your prototype to the point where it can answer those questions. For example, if you need to test if users understand your indication of the sort order for a table, all you need is a paper picture of the table showing the sort indication (with the table contents blurred) and ask them how the table is sorted. If you need to test the IA, all you need is a bunch of web pages, empty except for a title, that are linked through the navigation menus.

You only need the pages relevant for the tasks you give your users. If you’re just testing the IA, then you only need the pages on the normative path. If you are also testing error recovery, then you need the pages off the normative path along with the full navigation controls. If you are also testing error detection, then you need content on the pages as well.

You can also simulate functionality when that’s easier to do. For example, in testing if users can figure out how to get a desired sort order, when the user clicks on a non-functioning control for sorting the table, you can say, “Okay, doing that will get you this,” and you take the mouse and select a bookmark that shows the table in the new sort order.

In hallway testing, if users breach the fidelity envelope, you can simply say, “I haven’t made that part yet. Let’s go back to A, and continue from there.” Of course, you should note that the user made a wrong turn in the task you intended for them. I haven’t had any problems with users complaining about non-functional features when I tell them up front it’s an incomplete prototype and we’re only testing the UI for features x, y, and z at the moment.

For low fidelity prototypes, I often call them “mockups” or “drawings” to users rather than “prototypes” to indicate the low functionality. You can put obvious placeholders in for missing content (e.g., “Blah, blah, blah…”, “TODO: Picture of product about here.”). If a user comments on something outside the fidelity envelope (e.g., “This symbol should be red to stand out more”), simply note it, and say that topic is under development (e.g., “Thanks. We haven’t started work on the colors yet. We’re just trying to figure out how to organize the site right now.”).

Usability testing with limited-fidelity prototypes is really necessary for iterative design to be feasible for most projects. Otherwise, you waste too much work developing things that have to be redone.