Usability testing shows how real people will use a product, software or web site in the real world.

The goals of usability testing vary by study, but they usually include:

• Identifying problems in the design of the product or service

• Uncovering opportunities to improve

• Learning about the target user’s behavior and preferences

Why do we need to do usability testing? Won’t a good professional UX designer know how to design a great user interface? Even the best UX designers can’t design a perfect — or even good enough — user experience without iterative design driven by observations of real users and of their interactions with the design.

There are many variables in designing a modern user interface and there are even more variables in the human brain. The total number of combinations is huge. The only way to get UX design right is to test it.

Elements of Usability Testing

There are many different types of usability testing, but the core elements in most usability tests are the facilitator, the tasks, and the participant.

The facilitator administers tasks to the participant. As the participant performs these tasks, the facilitator observes the participant’s behavior and listens for feedback. The facilitator may also ask followup questions to elicit detail from the participant.

Facilitator

The facilitator guides the participant through the test process. She gives instructions, answers the participant’s questions, and asks followup questions.

The facilitator works to ensure that the test results in high-quality, valid data, without accidentally influencing the participant’s behavior. Achieving this balance is difficult and requires training.

(In one form of remote usability testing, called remote unmoderated testing, an application may perform some of the facilitator’s roles.)

Tasks

The tasks in a usability test are realistic activities that the participant might perform in real life. They can be very specific or very open-ended, depending on the research questions and the type of usability testing.

Examples of tasks from real usability studies:

• Your printer is showing “Error 5200”. How can you get rid of the error message?

• You're considering opening a new credit card with Wells Fargo. Please visit http://wellsfargo.com and decide which credit card you might want to open, if any.

• You’ve been told you need to speak to Tyler Smith from the Project Management department. Use the intranet to find out where they are located. Tell the researcher your answer.

Task wording is very important in usability testing. Small errors in the phrasing of a task can cause the participant to misunderstand what they’re asked to do or can influence how participants perform the task (a psychological phenomenon called priming).

Task instructions can be delivered to the participant verbally (the facilitator might read them) or can be handed to a participant written on task sheets. We often ask participants to read the task instructions out loud. This helps ensure that the participant reads the instructions completely, and helps the researchers with their notetaking, because they always know which task the user is performing.

Participant

The participant should be a realistic user of the product or service being studied. That might mean that the user is already using the product or service in real life. Alternatively, in some cases, the participant might just have a similar background to the target user group, or might have the same needs, even if he isn’t already a user of the product.

Participants are often asked to think out loud during usability testing (called the “think-aloud method”). The facilitator might ask the participants to narrate their actions and thoughts as they perform tasks. The goal of this approach is to understand participants’ behaviors, goals, thoughts, and motivations.