Nielsen Norman GroupEvidence-Based User Experience Research, Training, and Consulting
Usability findings derived from a broad base of diverse studies have higher credibility than those based on many users with a single stimulus.
Users generally prefer designs that are fast and easy to use, but satisfaction isn't 100% correlated with objective usability metrics.
User testing can be done anywhere; witness our international studies, carried out with equipment that fit in a carry-on bag.
What's worth the most: field studies or user tests? Depends on your company's usability maturity, but user testing is the safe bet if you can do only one thing.
3 approaches to better design: each has its uses, but the costs, benefits, and risks differ dramatically.
Better to accept a wider margin of error in usability metrics than to spend the entire budget learning too few things with extreme precision.
Despite many weaknesses, interviews are a valuable method for exploratory user research.
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.
It's easy to bias study participants, whether in user testing or in card sorting, if they focus on matching stimulus words instead of working on the underlying problem.
Enemies of usability claim that because 'the experts disagree,' they can safely ignore user advocates' expertise and run with whatever design they personally prefer.
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.
Using a linear diagram to plot data from website traffic logs can lead you to overlook important conclusions. Sometimes advanced visualizations are worth the effort.
The relative popularity of a site's pages, the number of visitors referred by other sites, and the traffic from search queries continue to follow a Zipf distribution.
When collecting usability metrics, testing 20 users typically offers a reasonably tight confidence interval.
Usability goes beyond the level of individual users interacting with screens. It's also a question of how easy or cumbersome it is for the entire organization to use a system.
Measuring the live impact of design changes on key business metrics is valuable, but often creates a focus on short-term improvements. This near-term view neglects bigger issues that only qualitative studies can find.
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.
Testing ever-more users in card sorting has diminishing returns, but you should still use three times more participants than you would in traditional usability tests.
To ensure high response rates and avoid misleading survey results, keep your surveys short and ensure that your questions are well written and easy to answer.
Designs that engage and empower users increase their enjoyment and encourage them to explore websites in-depth. Once we achieve ease of use, we'll need additional usability methods to further strengthen joy of use.
Field studies should emphasize the observation of real user behavior. Simple field studies are fast and easy to conduct, and do not require a posse of anthropologists: All members of a design team should go on customer visits.
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.
Focus groups and surveys study users' opinions - not actual behavior - so they are misleading for the design of interactive systems like websites. Automated usability measures are just as misleading.
How to collect usability data from site users, using a historical archive as the case study. Keep surveys simple, collect data from real-world usage, and get feedback from friends of the site.
Website usage must be tracked to plan server capacity needs and future business models. Examples show use of regression statistics to predict future traffic patterns.
Focus groups can be a powerful tool in system development, but they should not be the only source of information about user behavior. In interactive systems development, the proper role of focus groups is not to assess interaction styles or design usability, but to discover what users want from the system.
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.
Because computers are no longer used exclusively for utilitarian tasks, we should use systematic methods to design products that are not just efficient but also attractive to users.
Participants in a course on usability inspection methods were surveyed 7-8 months after the course. Factors which influenced adoption were cost, rated benefit of the method, relevance to current projects, and whether the methods had active evangelists.
Paper prototyping, card sorting, and traditional usability testing were all employed to guide the design of the 1995 Sun Microsystems' Web site.
Extensive usability testing was conducted to guide the 1995 Sun Microsystems' Web site design. This series of articles describes in detail the methods and findings of the design team.
Heuristic evaluation is a good method of identifying both major and minor problems with an interface, but the lists of usability problems found by heuristic evaluation will tend to be dominated by minor problems, which is one reason severity ratings form a useful supplement to the method.
Rating usability problems according to their severity facilitates the allocation of resources to fix the most serious problems. Severity ratings are a combination of frequency, impact, and persistence.
Usability inspection is the generic name for a set of methods that are all based on having evaluators inspect a user interface. Typically, usability inspection is aimed at finding usability problems in the design, though some methods also address issues like the severity of the usability problems and the overall usability of an entire system.
Heuristic evaluation involves having a small set of evaluators examine the interface and judge its compliance with recognized usability principles (the "heuristics"). Adherence to specific methods can improve the outcome of an heuristic evaluation.
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.
This essay describes a technique for extending a task analysis based on the principle of goal composition. Basically, goal composition starts by considering each primary goal that the user may have when using the system. A list of possible additional features is then generated by combining each of these goals with a set of general meta-goals that extend the primary goals.