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Crash Course Lesson on Usability Testing

The extreme, extreme basics...

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Usability Testing is NOT...

“What type of feedback did you gather from your usability participants?”

“I showed my program to three different people and they all said it looked really, really good.”

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Usability Testing- Definition

Usability testing is a method by which users of a product are asked to perform certain tasks in an effort to measure the product's ease-of-use, task time, and the user's perception of the experience. Changes are made to the application or site based on the findings of the usability tests. Usability test participants are encouraged to think aloud and voice their every opinion. Usability testing is best used in conjunction with a user-centered design process, a method by which a product is designed according to the needs and specifications of users.

Adopted from http://searchwebmanagement.techtarget.com/sDefinition/0,,sid27_gci214526,00.html

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Why is Usability Testing Necessary?

User, Designer, Programmer each have different models.

The designer’s intuition is not always correct. It’s impossible to predict usability from

appearance. Design standards and guidelines are not

sufficient. Competitive advantages and reduced support

costs.

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What information to provide?

Give a brief explanation that the participant’s involvement is to solicit user feedback. Any problems are the fault of the software.

In real-world situations explain confidentiality agreement, liability legalities, and that participant is free to leave at any time (and still get paid).

Provide instructions as to the user’s task but not explanations of the software.

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What to User Test?

Possibilities include: Conformance with a requirement Conformance with guidelines for good design Identification of design problems Ease of system learning Retention of learning over time Speed of task completion Error rates Subjective user satisfaction

Galitz, W. O., (2002) The Essential Guide to User Interface Design, 2nd Edition, Wiley Computer Publishing, New York, NY.

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What questions to ask?

Depends on which phase of the development cycle- what can be changed? Conceptual model? Layout? Fonts?

There should be a list of questions of the major design issues that is prepared in advance. There should be specific question(s) that the usability testing is designed to answer. Usability testing has specific objectives.

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What is the Goal of Usability Testing?

Usability testing should be designed to determine if the software is meeting the

Qualitative Usability Goals Quantitative Usability Goals

Adapted from Mayhew, Deborah J. (199) The Usability Engineering Lifecycle

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Qualitative Usability Goals- Examples

The design must support users working in a high-interrupt environment, with lots of context information on screen to remind users where they are when they get distracted.

The design must support very infrequent users of a very complex task. Thus, it must be self-explanatory, easy to learn and remember.

Adapted from Mayhew, Deborah J. (199) The Usability Engineering Lifecycle

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Quantitative Usability Goals - Examples

Experienced users (defined as users who have performed the task five times in a training session) should take no longer than 15 seconds minutes on average to address an email.

Novice users (defined as first-time users) should take no longer than three minutes to complete the registration input form.

Adapted from Mayhew, Deborah J. (199) The Usability Engineering Lifecycle

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When to ask questions?

If you are worried about interrupting the task flow of your participant, then ask the question after the completion of the task.

If you are more worried about the participant forgetting their current thought process than interrupting, then ask right away.

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Thinking Aloud Protocol

During a usability test, instruct participants to verbalize their thoughts aloud protocol. The usability testers prompt participants by asking direct questions about the software, in order to understand their mental model of the system and the tasks, and where they have trouble in understanding and using the system.

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Co-discovery Method

During a usability test, two participants perform tasks together while being observed. In order to increase the amount of communication to gain insight to their thought process, one participant is assigned the mouse and the other the keyboard. They are to help each other in the same manner as they would if they were working together to accomplish a common goal using the product.