Nielsen Norman GroupEvidence-Based User Experience Research, Training, and Consulting
Usability is a quality attribute that assesses how easy user interfaces are to use. The word "usability" also refers to methods for improving ease-of-use during the design process.
Usability is defined by 5 quality components:
Usability 101: Introduction to Usability
First Rule of Usability? Don't Listen to Users
Users aged 65 and older are 43% slower at using websites than users aged 21–55. This is an improvement over previous studies, but designs must change to better accommodate aging users.
If using web or browser-related terms, consider defining them in place to make websites easier for senior citizens. Avoid using technical words if they are not necessary.
Long listings might need pagination by default, but if users customize the display to View All list items, respect that preference.
Teens are (over)confident in their web abilities, but they perform worse than adults. Lower reading levels, impatience, and undeveloped research skills reduce teens’ task success and require simple, relatable sites.
The user's target was at the top of the page in 98-point font. But she failed to find it because the panel auto-rotated instead of staying still.
Users generally prefer designs that are fast and easy to use, but satisfaction isn't 100% correlated with objective usability metrics.
Web design is stabilizing; the average homepage is only about 40% different than it was a year before, corresponding to 3 years between complete redesigns.
Users don't see stuff that's right on the screen. Selective attention makes people overlook things outside their focus of interest.
Page design itself scores 15% higher than the 2002 Olympics site. But a disjointed overall Internet presence leads to an intolerable overall user experience.
When a multinational company produces a localized country site, usability is often lost. Local advertising agencies design good-looking sites that don't communicate.
Reasonably big monitors have finally become the most common class of desktop computer screen, dethroning the 1024×768 resolution that was long the target for web design.
Smooth-flow task performance makes application use pleasurable. But disruptions are all too common due to crinkly design or creaking implementation.
'Chrome' is the user interface overhead that surrounds user data and web page content. Although chrome obesity can eat half of the available pixels, a reasonable amount enhances usability.
What is usability? How, when, and where to improve it? Why should you care? Overview answers basic questions + how to run fast user tests.
Sites have improved, and we now know much more about e-tailing usability. Today, poor content is the main cause of user failure.
Users often leave Web pages in 10-20 seconds, but pages with a clear value proposition can hold people's attention for much longer because visit-durations follow a negative Weibull distribution.
Once users reject a design technique due to repeated bad experiences it's almost impossible to use it for good because people will avoid it every time.
The ten most egregious offenses against users. Web design disasters and HTML horrors are legion, though many usability atrocities are less common than they used to be.
Users pay close attention to photos and other images that contain relevant information but ignore fluffy pictures used to 'jazz up' Web pages.
Slow page rendering today is typically caused by server delays or overly fancy page widgets, not by big images. Users still hate slow sites and don't hesitate telling us.
Over the past decade, usability improved by 6% per year. This is a faster rate than most other fields, but much slower than technology advances might have predicted.
From 0.1 seconds to 10 years or more, user interface design has many different timeframes, and each has its own particular usability issues.
Usability scores for 51 websites show some correlation between navigation, content, and feature quality, but no connections to other usability areas.
Finding addresses and location information on company websites has gotten dramatically easier, but users increasingly turn to search engines first for this task.
Bad content, bad links, bad navigation, bad category pages... which is worst for business? In these examples, bad content takes the prize for costing the company the most money.
Users now do basic operations with confidence and perform with skill on sites they use often. But when users try new sites, well-known usability problems still cause failures.
AJAX, rich Internet UIs, mashups, communities, and user-generated content often add more complexity than they're worth. They divert design resources and prove that what's hyped is rarely what's most profitable.
A site did most things right, but still had a miserable 14% success rate for its most important task. The reason? Users ignored a key area because it resembled a promotion.
Users rarely look at display advertisements on websites. Of the 4 design elements that do attract a few ad fixations, one is unethical and reduces the value of advertising networks.
A remarkable 80% of findings from the Web usability studies in the 1990s continue to hold today.
Making users suffer a drop-down menu to enter state abbreviations is one of many small annoyances that add up to a less efficient, less pleasant user experience. It's worth fixing as many of these usability irritants as you can.
Several usability findings lead directly to higher sales and increased customer loyalty. These design tactics should be your first priority when updating your website.
Although the gains don't fall into traditional profit columns, there are clear arguments for improving usability of non-commercial websites and intranets. In one example, a state agency could get an ROI of 22,000% by fixing a basic usability problem.
Although gift features leverage the online medium and draw new users to a site, they also introduce many usability pitfalls. Among them are poorly designed email notifications, which many users simply ignore.
Selective list of recommended books on Web design, user interface design, usability engineering, hypertext, future user interfaces.
User interfaces in film are more exciting than they are realistic, and heroes have far too easy a time using foreign systems.
The early Web's explosive growth rate has slowed, but even the mature Web is still expanding and recently crossed the 100 M websites mark.
User testing shows that business-to-business websites have substantially lower usability than mainstream consumer sites. If they want to convert more prospects into leads, B2B sites should follow more guidelines and make it easier for prospects to research their offerings.
B2B sites often have overly complex pricing structures or can't show prices at all. To help prospects with early research, list representative cases and their prices.
Clear content, simple navigation, and answers to customer questions have the biggest impact on business value. Advanced technology matters much less.
6% of task attempts are extremely slow and constitute outliers in measured user performance. These sad incidents are caused by bad luck that designers can - and should - eradicate.
A strict focus on accessibility as a scorecard item doesn't help users with disabilities. To help these users accomplish critical tasks, you must adopt a usability perspective.
The oldies continue to be goodies - or rather, baddies - in the list of design stupidities that irk users the most.
Users from other countries have special needs related to entry fields for names and addresses, measurements and dates, and information about regional product standards.
Many design elements work for Amazon.com mainly because of its status as the world's largest and most established e-commerce site. Normal sites should not copy Amazon's design.
Despite posing well-known risks, websites continue to feature poorly designed scrollbars. Among the ongoing problems that result are frustrated users, accessibility challenges, and missed content.
300,000 words of usability essays have had an impact: online user interfaces are considerably easier to use now than they were in 1995. Many predictions and recommendations have come true, though the full Alertbox vision is far from realized.
About 90% of usability guidelines from 1986 are still valid, though several guidelines are less important because they relate to design elements that are rarely used today.
Studies of how people react to online advertisements have identified several design techniques that impact the user experience very negatively.
User interface guidelines for when to use a checkbox control and when to use a radio button control. Ten other usability issues for checkboxes and radio buttons.
Users expect 77% of the simpler Web design elements to behave in a certain way. Unfortunately, confusion reigns for many higher-level design issues.
Reduce the bounce rate for organic landing pages, collect data to manage PPC for maximum ROI, and take 6 other steps to maximize your site's holiday sales potential before it's too late.
Simple, unobtrusive designs that support users are successful because they abide by the Web's nature -- and they make people feel good.
Unless you have explicit links to product pages from article content, users who visit articles directly from search engines might never realize that you sell related products.
B2B websites must support a more complex buying process than B2C sites. Three key goals are to make a buyer's shortlist, offer a downloadable advocacy kit, and build a reputation for great service.
Sites are getting better at using minimalist design, maintaining archives, and offering comprehensive services. However, these advances entail their own usability problems, as several prominent mistakes from 2003 show.
Ten usability mistakes are made by about two-thirds of corporate websites. The prevalence of these errors alone warrants attention, especially since they appear on sites with significant investment in usable design.
I've published 200 Alertbox columns on the Web since 1995; in addition to achieving key victories over multi-million-dollar special interests and enemies of usability, the column's readership statistics validate the practice of archiving content.
Misconceptions about usability's expense, the time it involves, and its creative impact prevent companies from getting crucial user data, as does the erroneous belief that existing customer-feedback methods are a valid driver for interface design.
Users get lost inside PDF files, which are typically big, linear text blobs that are optimized for print and unpleasant to read and navigate online. PDF is good for printing, but that's it. Don't use it for online presentation.
Web users are highly goal-driven, and ads that interfere with their goals will be ignored. To succeed, ads must work with the medium, as well as with the user's aims and mindset.
Text-only advertisements work far better than banners, but is this only due to their novelty? Search engine text ads will retain their superiority over time, but text ads on other sites will work only if they focus on directly meeting users' needs.
On average, sample sites evenly distributed valuable screen space between content, navigation, fluff, blank areas, and system overhead. Areas of user interest should occupy more than the current 39%.
Jakob Nielsen's recommended hotlist of links to online columns, articles, and other websites about Web design, usability, and user interfaces.
Every year brings new mistakes. In 2002, several of the worst mistakes in Web design related to poor email integration. The number one mistake, however, was lack of pricing information, followed by overly literal search engines.
Usability tests of 46 Flash applications identified basic issues related to the ephemeral nature of Web-embedded apps. Some findings restate old truths about GUIs; others reflect the Net's new status as nexus of the user experience.
Flash designs are easier for users with disabilities to use when designers combine visual and textual presentations, minimize incessant movement, decrease spacing between related objects, and simplify features.
Tiny text tyrannizes users by dramatically reducing task throughput. IE4 had a great UI that let users easily change font sizes; let's get this design back in the next generation of browsers.
Over the last 1.5 years, the average compliance with established usability guidelines increased by 4%. If we can sustain this level of improvement, we'll reach the ideal of 90% guideline compliance in 2017.
A company's homepage is its face to the world and the starting point for most user visits. Improving your homepage multiplies the entire website's business value, so following key guidelines for homepage usability is well worth the investment.
Most site maps fail to convey multiple levels of the site's information architecture. In usability tests, users often overlook site maps or can't find them. Complexity is also a problem: a map should be a map, not a navigational challenge of its own.
With current Web design practices, users without disabilities experience three times higher usability than users who are blind or have low vision. Usability guidelines can substantially improve the matter by making websites and intranets support task performance for users with disabilities.
These design guidelines are excerpted from our book Homepage Usability: 50 Websites Deconstructed which contains more details, including copiously annotated screenshots of 50 homepages.
User success rates on e-commerce sites are only 56%, and most sites comply with only a third of documented usability guidelines. Given this, improving a site's usability can substantially increase both sales and a site's odds of survival.
To design an easy-to-use interface, pay attention to what users do, not what they say. Self-reported claims are unreliable, as are user speculations about future behavior.
A website's tagline must explain what the company does and what makes it unique among competitors. Two questions can help you assess your own tagline: Would it work just as well for competitors? Would any company ever claim the opposite?
When we asked users to find a nearby store, office, dealership, or other outlet based on information provided at a parent company's website, users succeeded only 63% of the time. On average, the 10 sites we studied complied with less than half of our 21 usability guidelines for locator design.
Forcing users to browse PDF files makes usability approximately 300% worse compared to HTML pages. Only use PDF for documents that users are likely to print. In those cases, following six basic guidelines will minimize usability problems.
Opponents of the usability movement claim that it focuses on stupid users and that most users can easily overcome complexity. In reality, even smart users prefer pursuing their own goals to navigating idiosyncratic designs. As Web use grows, the price of ignoring usability will only increase.
Flash reduces usability for three reasons: it makes bad design more likely, it breaks the Web's fundamental interaction style, and it consumes resources that would be better spent enhancing a site's core value.
Websites have to reduce their differences and allow advanced features to either become standard across sites or be extracted from the sites altogether and placed in the browser. Focus on services and content; use a standard design.
Since 1995, the readership of the Alertbox has grown by 4,800%. Most of the 105 old usability columns remain valid to this day since people change more slowly than the technology. But the Alertbox has encountered some setbacks as well.
Napster, IE 5 for the Mac, and Yahoo FinanceVision introduce specialized Internet UIs beyond the standard page viewing that had been unchanged since Mosaic.
Most Web forms would have improved usability if the Reset button was removed. Cancel buttons are also often of little value on the Web.
Micropayments will start with value-added content; mobile access; advice and sales become unbundled and physical experience environments may launch.
Ten design elements that would increase the usability of virtually all websites if only they were employed more widely.
The basic ideology of the Internet is bit transport; we need a utility-focused human-centered ideology for its fundamental architecture and protocols.
Standards ensure a consistent vocabulary, but don't limit designers' freedom (and responsibility) in deeper design issues. Also: Guidelines for writing design standards.
Partitioning the Web into N unlinked or otherwise isolated parts will reduce its overall value by a factor of N. A proprietary AOL instant messaging system will be worth only 4% of the full potential, and 1/3 will be completely lost.
New official standards make it easy to get the top priorities right and make websites accessible for users with disabilities (e.g., blind users who can't see images). But the single-design approach may be nearing the end of its life.
New technology and conventions have led to several new classes of usability problems in Web design.
Major websites violate 16% of the top ten mistakes in Web design on the average; huge corporate sites have many more design mistakes than the most popular sites.
Nine of ten mistakes in Web design identified in May 1996 still cause severe usability problems and should be avoided in modern websites.
Users continue to type and guess URLs and domain names, so Web usability can be improved by better URLs. In the long term this machine-level addressing scheme must be hidden.
A survey of 1,780 people who have bought something on the Web found that convenience and ease of use are the main reasons to shop on the Web. Non-buying visits (product research) are important to shoppers.
Mobile access becomes 3rd Killer App for the Internet, Web standards rebound, customer service is automated, e-commerce patents are issued, and the Web has its own Y2K problems
Yahoo has great usability and huge traffic because it embraces the characteristics of the Internet medium: minimalist design and many structured links. But Yahoo may not scale to keep up with the growth of the net.
Most corporate sites are so bad that Web usability problems cost a large company millions of dollars per year. On average, users fail when they try to accomplish tasks on the Web.
Jakob Nielsen's 1998 predictions of sessions he might present ten years later, at the 2008 Internet World conference.
Users' bandwidth grows by 50% per year (10% less than Moore's Law). The new law fits data from 1983 to 2010.
The 1997 redesign of the Sun Microsystems' Web site aimed to improve the visual appearance, ease of navigation, and performance of the Web site.
Most findings about Web usability from 1994 continue to hold. Scrolling pages and imagemaps are less of a problem; users now demand comprehensive sites.
CSS promotes site consistency and improved usability if linked (not embedded), centrally designed (not by page authors), and actively evangelized with example-rich style manuals. Respect user preferences.
The telephone is a better metaphor than television for thinking about the Web and its potential: the Web is a 1-to-1, narrowcast, low bandwidth medium that is user-driven and where everybody can publish content.
Comparing the nature of the Web as a medium when accessed through television sets and when accessed through computers, concluding that the level of user engagement is a main differentiator
Users' reactions to early design ideas for the Sun Microsystems' 1997 Web site demonstrate that users are becoming more web sophisticated, and prefer straightfoward access to content.
Two major trends will revive the Web as a useful tool beyond the current hype and uselessness.
frames, usability, hypertext, navigation, Web pages, unified conceptual model, atomic unit of Web content
Some "minor" details of web design--such as font size, text color, and image cropping-- can have important consequences for Web usability.
How to design Web sites that are accessible for users with various disabilities. Includes advice for designing for users with visual, auditory, motor, and cognitive disabilities. Using good ALT-tests is only one of the rules.
This article has attracted millions of page views since it was written in 1996, but most sites *still* commit these basic usability bloopers.
One frequently finds newspaper articles about the Internet or the World Wide Web stating that the number of servers on the WWW is doubling every 53 days. I don't believe in the 53-day estimate any more.
Screenshots and descriptions of 9 of the homepage versions created for the Sun Microsystems' 1995 Web site redesign effort, and tested with users to optimize the layout and content.
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.
Excerpt from Jakob Nielsen's 1995 book, Multimedia and Hypertext: The Internet and Beyond, offers predictions for the short term (3 to 5 year) and medium term (5 to 10 year) and long term (10 to 20 year) future of hypertext and the internet.
The 10 most general principles for interaction design. They are called "heuristics" because they are more in the nature of rules of thumb than specific usability guidelines.
This excerpt from Jakob Nielsen's book Usability Engineering describes how users react to different response time delays.