Usability testing is the most common technique to check how usable your interface is from the human center design framework. The power of this qualitative technique is that it focus on what the user do and not what the user say.
Usability testing reduces the risk of building the wrong thing. It saves money, time and other precious resources. It finds problems when they are still easy and cheap to fix.
When a designer is working on some assignment and when the design is almost finished, he may not realise that something could be improved until the proposed solution is tested by real users.
The usability testing is an iterative process, there is no silver bullet, you need to repeat the process until the design is not confusing anymore and your users are able to complete the scenarios you propose.
Usability testing process consists of the following phases:
Planning: During this phase the goals of usability test are determined. Having volunteers sit in front of your application and recording their actions is not a goal. You need to determine critical functionalities and objectives of the system. You need to assign tasks to your testers, which exercise these critical functionalities. During this phase, the usability testing method, number & demographics of usability testers, test report formats are also determined.
Recruiting: During this phase, you recruit the desired number of testers as per your usability test plan. Finding testers who match your demographic (age, sex etc.) and professional ( education, job etc.) profile can take time.
Usability Testing: During this phase, usability tests are actually executed.
Data Analysis: Data from usability tests is thoroughly analyzed to derive meaningful inferences and give actionable recommendations to improve the overall usability of your product.
Reporting: Findings of the usability test is shared with all concerned stakeholders which can include designer, developer, client, and CEO.
Research (Virzi, 1992 and Neilsen Landauer, 1993) indicates that5 users are enough to uncover 80% of usability problems. Some researchers suggest other numbers.
The truth is , the actual number of the users required depends on the complexity of the given application and your usability goals. Increase in usability participants results into increased cost , planning , participant management and data analysis.
But as a general guideline, if you are on a small budget and interested in DIY usability testing 5 is a good number to start with. If budget is not a constraint it’s best to consult experienced professionals to determine the number of users.
As with anything in life, usability testing has its merits and de-merits. Let’s look at them.
However, these costs pay themselves up in form of higher customer satisfaction, retention and repeat business. Usability testing is therefore highly recommended.
After you have received the results of your website usability tests, the first thing you should do is compile the information and take note of any issues that testers had in common. Look at the amount of time it took them or their test subjects to complete various tasks and think about what you can change so that users are able to complete these tasks faster. Also note any feedback you have been given by the testers and where this is not clear, do contact them to clear out any ambiguities. Make any changes you can to improve the usability of your site as soon as possible. As with any form of website testing, usability testing is an ongoing process so be sure to run usability tests again after you have made changes. This not only ensures that the changes you made were appropriate but will additionally help you discover new usability problems.