Nielsen Norman GroupEvidence-Based User Experience Research, Training, and Consulting
Watching users try to complete tasks with your interface is the most effective and productive way to uncover usability problems.
User testing can be done anywhere; witness our international studies, carried out with equipment that fit in a carry-on bag.
The answer is 5, except when it's not. Most arguments for using more test participants are wrong, but some tests should be bigger and some smaller.
3 approaches to better design: each has its uses, but the costs, benefits, and risks differ dramatically.
Simple usability tests where users think out loud are cheap, robust, flexible, and easy to learn. Thinking aloud should be the first tool in your UX toolbox, even though it entails some risks and doesn't solve all problems.
What is usability? How, when, and where to improve it? Why should you care? Overview answers basic questions + how to run fast user tests.
Better to accept a wider margin of error in usability metrics than to spend the entire budget learning too few things with extreme precision.
In pilot studies, you can occasionally relax the need for real users and let members of your own team serve as test participants. It's good for them.
3 methods for increasing UX quality by exploring and testing diverse design ideas work even better when you use them together.
Besides usability specialists, all design team members should observe usability. It's also good to invite executives. Although biased conclusions are possible, they're far outweighed by the benefits of increased buy-in and empathy.
It's more difficult to conduct usability studies with experienced users than with novices, and the improvements are usually smaller. Still, improving expert performance is often worth the effort.
Usability is like cooking: everybody needs the results, anybody can do it reasonably well with a bit of training, and yet it takes a master to produce a gourmet outcome.
Simple user testing with 5 participants, paper prototyping, and heuristic evaluation offer a cheap, fast, and early focus on usability, as well as many rounds of iterative design.
Even the tiniest amount of empirical facts (say, observing 2 users) vastly improves the probability of making correct UI design decisions.
User experience research methods can answer a wide range of questions. Know when to use each method by mapping them in 3 key dimensions and across typical product development phases.
TiVo ran 12 user tests in 12 weeks while designing its new website. As TiVo's experience shows, frequent and regular testing keeps the design usability focused.
The 1% of websites that don't suck can be made even better by strengthening exceptional user performance, eliminating miscues, and targeting company-wide use and unmet needs.
Since I started in 1983, the usability field has grown by 5,000%. It's a wonderful job - and still a promising career choice for new people.
Depending on how representative designers are of the target audience, a project might need more or less user testing. Still, usability concerns never go away completely.
Computing the net present value (NPV) lets you estimate the most profitable level of usability investment. For big projects, expensive usability can pay off.
Testing 5-10 users at once lets you conduct large-scale usability testing and still meet your deadlines.
Having a specialized usability person is best, but smaller design teams can still benefit when designers do their own user testing and other usability work.
You get the same insights regardless of where you conduct user testing, so there's no reason to test in multiple cities. When a city is dominated by your own industry, however, you should definitely test elsewhere.
Don't run your studies for the benefit of the people in the observation room. Test to discover the truth about the design, even when user tasks are boring to watch.
When collecting usability metrics, testing 20 users typically offers a reasonably tight confidence interval.
Up to 40% of precious testing time is wasted while users engage in nonessential activities. Far better to focus on watching users perform tasks with the target interface design.
Most usability practitioners don't derive full value from their user tests because they don't systematically archive the reports. An intranet-based usability archive offers four substantial benefits.
Formal reports are the most common way of documenting usability studies, but informal reports are faster to produce and are often a better choice.
Despite being an artificial situation, user testing generates realistic findings because people engage strongly with the tasks and suspend their disbelief.
User research offers a learning opportunity that can help you build an understanding of user behavior, but you must resolve discrepancies between research findings and your own beliefs.
Number fetishism leads usability studies astray by focusing on statistical analyses that are often false, biased, misleading, or overly narrow. Better to emphasize insights and qualitative research.
How can a small company's website benefit from usability activities despite a minuscule budget? By integrating four simple and effective usability practices into the design process.
Professionally run design agencies user test their designs to increase the value they deliver to their clients. The challenge is getting clients to understand the benefits of a solid development methodology.
Easy test user recruiting is crucial to an effective usability process. The average per-user cost is $171, but varies greatly depending on location and the targeted profession.
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.
Elaborate usability tests are a waste of resources. The best results come from testing no more than 5 users and running as many small tests as you can afford.
Details in measurement methodology make the results of a recent market research study irrelevant for predicting real user behavior on the Web.
By turning all text into gibberish, a usability test can focus on whether the *layout* of a Web template helps users navigate and use the page.
Across 50 teams, the average time needed for their first usability test of a website was 39 hours. The average site had 11 usability catastrophes that prevented users from completing their tasks.
Discount usability engineering is our only hope. We must evangelize methods simple enough that departments can do their own usability work, fast enough that people will take the time, and cheap enough that it's still worth doing. The methods that can accomplish this are simplified user testing with one or two users per design and heuristic evaluation.
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.
Icons for the Sun Microsystems' 1995 Web site design were designed and tested in several iterations, both independent of and in context with the full Web site design.
Paper prototyping, card sorting, and traditional usability testing were all employed to guide the design of the 1995 Sun Microsystems' Web site.
A summary of statistics for the thirteen 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 CAUSE tools for computer-aided usability engineering. Nielsen, J. (1994). Usability laboratories. Behaviour & Information Technology 13, 1&2, 3-8.
Using Discount Usability Engineering to Penetrate the Intimidation Barrier,' paper by Jakob Nielsen on simpler and cheaper ways to a better UI;with examples of fast usability projects.
Summary of usability results conducted in 1994 on the web sites of Hewlett-Packard, IBM, Microsoft, Sun Microsystems, and Time Warner; the report includes screen captures of several famous early websites and because it is one of the first formal usability studies of the Web.
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. Nielsen, J. (1993). Iterative user interface design. IEEE Computer 26, 11 (November), 32-41.