The usability test essentially works by setting your participant some tasks to complete on your website (software, application, interface… whatever it is). Asking them to think out loud, you aim to record how they get on, gain insights into their thought processes, and flag any problems that are identified.
Part 1: Usability Testing is Easy
Part 3: Reviewing the problems
So how do you design a task?
For this, you need to have an idea of the goals of your users when they are on your website, and the common activities they perform whilst trying to achieve those goals. You don’t necessarily need to go into a lot of detail, perhaps at early stages of testing, or where you are testing the whole system (as opposed to a specific interface or feature), so don’t get too worried about needing to produce exhaustive task analyses.
List some key activities, and then prioritise them. Aim to build up a set of tasks that cover the likely uses of your different user groups, and that meet differing technical abilities, if appropriate.
Dado Marcora demonstrated a usability test of the new BioMart interface that he is responsible for designing and developing. An example activity for a user might be
finding all the mouse genes on the first 10 megabases of chromosome 2
Fine, but let’s work that into a small scenario, so that your participant can get into it a little bit more.
You are a bioinformatician working on the involvement of certain genes and their homologues in cancer development. At the moment, you are working on chromosome 2, and you need to produce a list of genes to include in a paper. You use BioMart to generate this list.
So something a little bit more chatty, and also something that could be linked to other scenarios, so that the user gets the idea of a theme, perhaps. As Christine Perfetti says, you want to get across to your participant why they would be doing this task at all, so put it in context.
Right user, right task
It is really important to give the right task to the right user. Hopefully, when you have recruited your test participants, you will have gathered some demographic data. This might be things like type of role (e.g. bioinformatician, industry researcher, wet lab biologist, etc), how much they rely on computers and websites for their work, familiarity with your application (or those of “competitors”), and so on.
Divide your users into user groups, and make a note of their relative abilities and levels. Aim to write tasks that fit these different groups and “strata” wherever possible. If you give a completely unfamiliar or advanced task to a user, the test is going to take a nose-dive!
Jenny Cham produced lots of these kinds of short scenarios for a round of contextual enquiry and usability testing she did recently, and they proved very effective in engaging the participants, and encouraging them to think out loud. A bit of investigation into the kind of research that the participants are involved in allowed her to come up with very relevant and appropriate scenarios.
[Added Nov 25, 2011] I can highly recommend David Travis’ (UserFocus) article on “creating usability test tasks that really motivate users” – typically fine stuff!