Five Guiding Principles for Usability Testing

DevToolsGuy / Tuesday, September 24, 2013

Usability testing has long been used as an essential tool for user experience and user interface designers. Even with the most ideal requirements and the perfect project team, nothing compares to getting a product in front of real people for testing. Despite its simple nature, usability testing can be difficult to implement correctly. Here are five of our top tips on conducting great usability sessions:

1. Choosing the Right Subjects

The key here is that the results will only be as good as the people you test. If you pick a set of subjects who are completely unfamiliar with the system being tested, your results will likely be worthless.

When all is well, you will have developed ‘personas’ during the requirements or development process of the project. A persona is a realistic representation of a key audience segment for your website or service. Sets of personas are helpful when deciding on features to implement or functionality to design, as they give you a user reference point to consider.

When it comes to usability testing, it’s essential to try to match subjects against these personas. If you don’t have personas created for your product, now is a good time to write them, or at least create simple versions to help you decide who good subjects for testing will be.

2. Wording Tasks

When you are writing out tasks your subjects will carry out during testing, think about a court trial and examination by counsel. A loaded question, such as “is this feature fantastic?” is inherently biased, and the subjects answer will naturally be affected. Tasks should be simple, clear and free from your own (or your team’s) personal feelings. For example:

“Review the homepage and explain what elements catch your eye” is much more effective than, “Can you see the big banner at the top of the homepage?”

“Review the steps of the checkout process and rate the experience of each screen from 1 to 5, five being the best” will serve you better than, “Is the last step of the checkout process too complex? We think the icons are very small.”

3. How to Behave During a Session

If you are helping out in the session itself, such as getting subjects in and settled, handing out tasks, answering queries or taking notes, then you have to be especially careful. You need to say and do as little as possible, do not distract the subject, and don’t chip in during tasks, even if you know how to do them and the subject is struggling. In order to prevent yourself interfering with your own test, remember these three golden rules:

  • Don’t speak until you are spoken to.
  • Sit down during the session, ideally not directly behind or over the shoulder of the subject.
  • Only help the subject with practical things like logging on or system crashes. If they can’t complete a task, do not help them.

4. Recording Sessions and Feedback

The person running the task should be able to take notes, but they can expect to be busy with admin tasks and helping the subject, so it is best if you video record the session. The most effective usability results come from recordings of both the user (their reactions and body language) and the screen (movement of mouse and interactions with the system). The first recording can be done with a simple camera and tripod, or even an iPhone if you have nothing else. The second type of recording can be achieved with any number of desktop recording software packages, ranging from free, to feature packed premium purchases.

It goes without saying that you should get written consent to be recorded from each person before the session begins.

5. Gathering Feedback After a Session

Immediately after the session is finished and the subject has completed all tasks, be sure to conduct a quick interview or survey. This is a great way to capture really useful feedback, and questions can be tailored to what happened in the particular session. It is also a great way to get quotes or sound bites from attendees.