Usability Testing What it is and how to do it

1. Usability TestingWhat it is and how to do it Laura Ruel School of Journalism and Mass Communication University of North Carolina – Chapel Hill Sources: Hyde Post, AJC.comJohn Stasko, Georgia Tech

2. Usability testing • Basic definitionTesting the ease with which users can learnand use a product.

3. Usability testing • From WikipediaUsability testing is a means for measuring how well people can use some human-made object (such as a web page, a computer interface, a document, or a device) for its intended purpose • Usability testing focuses on a particular object or a small set of objects, whereas general human-computer interaction studies attempt to formulate universal principles. • If usability testing uncovers difficulties, such as people having difficulty understanding instructions, manipulating parts, or interpreting feedback, then developers should improve the design and test it again.

4. Usability testing • From Wikipedia, continued • During usability testing, the aim is to observe people using the product in as realistic a situation as possible, to discover errors and areas of improvement. • Designers commonly focus excessively on creating designs that look "cool", compromising usability and functionality. This is often caused by pressure from the people in charge, forcing designers to develop systems based on management expectations instead of people's needs. A designers' primary function should be more than appearance, including making things work with people.

5. Usability testing • From Wikipedia, continued • Caution: simply gathering opinions is not usability testing -- you must arrange an experiment that measures a subject's ability to use your document. 1 • Rather than showing users a rough draft and asking, "Do you understand this?", usability testing involves watching people trying to use something for its intended purpose. For example, when testing instructions for assembling a toy, the test subjects should be given the instructions and a box of parts. Instruction phrasing, illustration quality, and the toy's design all affect the assembly process.

6. Usability testing • From Wikipedia, continued • Setting up a usability test involves carefully creating a scenario, or realistic situation, wherein the person performs a list of tasks using the product being tested while observers watch and take notes. • Several other test instruments such as scripted instructions, paper prototypes, and pre- and post-test questionnaires are also used to gather feedback on the product being tested. • The aim is to observe how people function in a realistic manner, so that developers can see problem areas, and what people like. The technique popularly used to gather data during a usability test is called a think aloud protocol.

7. Usability testing • From Wikipedia, continued • Usability testing generally involves measuring how well test subjects respond in four areas: time, accuracy, recall, and emotional response. The results of the first test are the baseline or control measurement; all subsequent tests are compared to the baseline. • Time on Task -- How long does it take people to complete basic tasks? (For example, find something to buy, create a new account, and order the item.) • Accuracy -- How many mistakes did people make? (And were they fatal or recoverable with the right information?) • Recall -- How much does the person remember afterwards? • Emotional Response -- How does the person feel about the tasks completed? (Confident? Stressed? Would the user recommend this system to a friend?)

8. Usability testing • With individual interviews, you should find 80 percent of the problems with 5 interviews.

9. Usability testing • Step one: Design your study • Obviously you cannot analyze your entire presentation, nor can you study all the actions that all types of users might perform. • Decide on a category of users, define some tasks that they would do frequently, and choose four to five benchmark tasks to evaluate. • Carefully select these tasks to simulate what actual users of the site would do. • Once you have your tasks, design the experiment: decide on the procedure, etc.

10. Usability testing • Step two: Demographics • You must design a pre-experiment questionnaire to give your participant. It should gather appropriate background information (age, education, level of Internet use, etc.) that you will find useful in analyzing the performance data later.

11. Usability testing • Step three: Gather data • You must recruit at least one participant. • In a true usability test situation, all participants will need to read and sign an Informed Consent. Because this is not a formal test, you do not need to do this. • Gather your data in whatever manner is appropriate, given your design, your hypotheses, etc. You should include subjective and objective measures. • Carefully observe each session and take notes about the participant’s’ interactions with the site. Which tasks were performed successfully? How long did they take? Did the participant make errors? What problems occurred? Did the participant have a conceptual model of the site? Was it correct?

12. Usability testing • Step four: Post-task questionnaire • You will want to create and administer a written questionnaire (ideally 4 or 5 questions) to be given to the participant after the tasks are completed. • This questionnaire should gather some more subjective data, and should contain quantifiable inquiries. • Finally, plan a few open-format interview questions to ask the participant at the end of the session. These should elicit more overall, qualitative impressions of the website.

13. Usability testing • Step five: Analyze your data and make conclusions • This part will be the post-mortem for your project. • Inspect your data and determine if/how they address your hypotheses about your site. • What changes might you make to your site in light of the user’s experience? • Will these changes deviate from your original plan? Why? • What would you do differently if you had more time? Why?