A successful usability career requires some theoretical knowledge, but mainly rests on brainpower and many years' experience testing and studying users. The only way to gain that experience is to start now.
In addition to being expensive, collecting usability metrics interferes with the goal of gathering qualitative insights to drive design decisions. As a compromise, you can measure users' ability to complete tasks. Success rates are easy to understand and represent usability's bottom line.
Although measuring usability can cost four times as much as conducting qualitative studies (which often generate better insight), metrics are sometimes worth the expense. Among other things, metrics can help managers track design progress and support decisions about when to release a product.
The unprecedented international exposure afforded by the Web increases the designer's responsibility for ensuring international usability. Because of the myriad of issues in international usability, I recommend doing international usability testing with users from a few countries in different parts of the world. No guidelines yet published are sufficiently complete to guarantee perfect international usability, so an empirical reality check is always preferred.
When working on a product intended for use abroad your best bet is to conduct international usability testing. You may need to engage a translator or even a local usability consultant, depending on the complexity of the test.
A summary of statistics for 13 usability laboratories in 1994, an introduction to the main uses of usability laboratories in usability engineering, and survey of some of the issues related to practical use of user testing and computer-aided usability engineering.
In 4 case studies, the median usability improvement was 165% from the first to the last iteration, and the median improvement per iteration was 38%. Iterating through at least 3 versions of a UI design is recommended, since some usability metrics may decrease in some versions if a redesign has focused on improving other parameters.
In remote usability studies, it's hard to identify test participants who should not be in the study because they don't fit the profile or don't attempt the task seriously. This is even harder in unmoderated studies, but it can (and should) be done.
Usability studies with children and teenagers are as valuable as any other user research, but require special attention to both participant recruiting and study facilitation. You can't act the same with kids as you would with adults.
At the first Virtual UX Conference, Jakob Nielsen answered participant questions about topics ranging from user-experience careers and skill development to foldable smartphones and the future of user interfaces.
There are two ways to structure a UX research study when we're testing two (or more) designs: we can have each design tested by different people, or we can reuse the same users for all conditions. Each approach has some advantages and problems.
For 30 years, the recommendations have remained the same for improving usability in a UX design project on a tight budget: simplified user testing with 5 users, early test of paper prototypes, and heuristic evaluation.
How to conduct user research for systems with confidential or otherwise sensitive data, for example in domains like healthcare or financial services, where it can be problematic to record screens or otherwise share the user's information.
Usability testing and other UX evaluation methods can be divided into two major categories: formative evaluation and summative evaluation. Both have their place, but at different stages in the design lifecycle, and they have different characteristics, for example in the number of test participants needed for a good study.
Usability testing is similar to how wild animals hunt for food: we're trying to hunt down the design flaws in the user interface and must optimize a series of studies for total gain, rather than spend too much on any one study.
“That’s just one person” and “Our real users aren’t like that” are common objections to findings from qualitative usability testing. Address these concerns proactively to ensure your research is effective.