To conduct effective usability tests, you need to find real users whom you can observe while they use your product.
If you have a consumer product intended for sale to the general public, you’ll need to make sure that your user tests involve a matching diversity of people representative of your target audience.
If you have a specialized niche product, your pool of potential users may be small, but your potential subjects will be more motivated to participate, as your product promises to solve their particular problems and is tailored to their needs. You may have a harder time finding enough suitable users in your local area and so you may need to resort to “distance testing” via teleconferencing and screen-sharing software. Industry publications, professional associations, and discussion forums catering to your target audience can be useful for recruiting suitable participants.
Here are some ideas for sources of potential users:
- Friends and family
- Employees in your development team or department
- Employees from elsewhere in your organization
- Your existing customers
- Subscribers to your company/product newsletter or blog
- People at trade shows and conventions
- People in your professional network
- People recruited through advertisements
Recruiting your friends, family, and coworkers is often easier than other methods, but statisticians call this convenience sampling, and convenience samples introduce biases into your results. Your participants may not accurately represent the cross-section of users who will actually be buying and using your product, and so you may draw incorrect conclusions from your observations and usability tests.
If you solicit participants from the general public via advertising, you’ll usually need to offer an incentive, usually cash. But be aware that this can attract a certain kind of people. And there are many people whom you may want to reach but who will never respond: Not many high-powered lawyers earning $300 per hour will take an hour or two out of their busy schedule for a $50 gift certificate, for instance. And introverted individuals are less likely to sign up for usability testing sessions. Again, the main point here is that you need to make sure that the people you’re recruiting are a reasonable sample of your target audience, and if you suspect your sample is not representative, then you need to be aware of potential biases.
Recruiting participants and scheduling meetings can be time-consuming, so you may want to delegate this to an assistant. You also need to plan for the fact that a shockingly large percentage of people will not show up to their appointments. Reminder phone calls the day before the appointment can help, though.
How many users do you need for a usability testing study? One or two participants is too little (though better than nothing); ten is sometimes too many as you’ll usually see patterns emerging by then. Five to eight is a good target to aim for.