New terms and concepts will be added to the glossary on an ongoing basis. For more essays and insights on usability and user experience matters, vist the new Weblog UXculture.Com.

Affordance | Error Control | Forward Compatibility | Iatrogenic | Informate | Interoperate | Just-In-Time Information | Last-Mile Problem | Microprocessor | Microsoft | OODA | Readability | Reversibility | Satisfice | Topsight | Usage Expectation | User Centered Design | User Experience (UX) | Visibility |

Affordance: More precisely called "Visual Affordance." Coined by ecological psychologist James J. Gibson (1904-1979) and co-opted by usability pioneer Donald Norman, it has come to mean a visual clue that signals to a user how to interact with an object. For example, you see a door with a handle. You sense that you can open the door by giving the handle a pull. And in most cases, you'd be right. Of course, we've all had the experience where you have to push on a handle to get the door open. If that happens, you have a bad affordance on your hands.

Another example: you're reading a Web site, and some of the text is underlined and in a blue color. That's an affordance signaling clickability. What if it's underlined and blue, but not clickable? That's called a false affordance. And be on the lookout, too, for the hidden affordance. The right button is there somewhere, if only you could find it. The hidden affordance is why no one knows how to program their VCR.

Error Control: The system lets you know when you've made an error and lets you make a correction. It's not as good as error prevention (an ounce of prevention being worth a pound of cure), but it's often more feasible. >> To Top

Error Prevention: The system stops you from making errors through the use of constraints and forced functions. For example, if you order a sweater at an online clothing store, and the sweater is only available in Red, Orange, and Green, you'd only be given those options. A system lacking error prevention would allow you to select or input "Purple," and would have to catch the error somewhere downstream. >> To Top

Forward Compatibility: The idea that the system you use today, including the data you enter and any custom configurations you apply, has the foresight and flexibility to accommodate and adapt to future technology advances. In the interactive field, many designers and programmers have worked diligently to make new sites backward compatible to earlier Web browsers. However, given the emergence of new standards and the pace of technology, many clients are today focusing more on forward compatibility. >> To Top

Iatrogenic: Not technically a "usability" term. Iatrogenic is an adjective which qualifies an illness as being physician-induced. In other words, one remedy creates a new -- and often greater -- illness. This is a persistent hazard when revamping a user experience, and those working to create better user experiences ought to honor a portion of the Hippocratic oath: "To follow that system of regimen which, according to my ability and judgment, I consider for the benefit of my patients, and abstain from whatever is deleterious." >> To Top

Informate: Using information technology to create a knowledge-rich work environment. Informating strategies compliment automation, and move beyond some its potential pitfalls -- by making information available across an organization so that users can make better-informed business decisions. Social scientist Shoshana Zuboff coined the term in her 1989 book, "In the Age of the Smart Machine: The Future of Work and Power," a study of the challenges facing companies and their employees in moving from direct "hands on" control of physical machines to computer-mediated control through a digital interface. >> To Top

Interoperate: The ability to perform well across different, and even competing, platforms, technologies, and domains. The lack of interoperability -- due to standards wars and an absence of shared protocols -- often makes users reluctant to embrace new technologies for fear of the potential headache factor. The lack of interoperability also explains why the Americans and the Brits each think the other drives on the wrong side of the road. >> To Top

Just-In-Time Information: While some users read all the fine print before making a decision, most don't have that kind of time: they'd prefer to economize their intake of information. They do this by waiting to get up to speed until they face a specific decision. Too many systems neglect users in this economizing category, making information least accessible at the momement when it is most needed: the screen where the user has to make a major choice. With just-in-time information, the user can easily access the right information in the right place at the right time. >> To Top

Last-Mile Problem: A telecommunications term to the effect that even if your network infrastructure is complete, your prospective customers won't have access and you won't turn a profit until you run a line across that last mile into a home or business. And the challenges posed by these multiple instances of the last mile, across every neighborhood or business district, tend to be more difficult and costly to solve than the challenges of the earlier miles. Of course, from the point of view of the end user, the last mile is rightly viewed as the first mile. Thankfully, wireless technlogy tends to leapfrog right over such land-based mileage issues altogether. >> To Top

OODA: A decision-making model developed by military strategist John Boyd, a US Air Force Colonel, that includes four cognitive phases: Observe, Orient, Decide, and Act. To observe is to take in information from multiple channels, gain situational awareness. To orient is to synthesize, form a mental map of the situation, gain topsight. To decide is to render a judgement on the best course of action. To act is to execute that judgement. This is sometimes called the OODA loop, or used as a verb: "to OODA through obstacles."

Users trying to navigate a Web site or application take some or all of these steps, bounded by an inclination to satisfice. Some businesses have found OODA can help them create a more agile, dynamic culture. Boyd is also known for the following formula of a succesful team, which is as applicable to business strategy as it is to military operations: "People, ideas, hardware--in that order!" >> To Top

Readability: Indicates how easy a screen is for a user to read, based on visual design issues such as color, contrast, typography, and density. Many user experiences are lacking in strong readability, and this can be especially challenging for older users. Cascading style sheets, with the ability to dynamically change font sizes, offers a way forward. Done right, CSS requires a highly flexible approach to interface design. >> To Top

Reversibility: A compelling feature: when you make a mistake or change your mind, the system lets you reverse your earlier action. Many systems offer at least some reversibility, but neglect to tell the users what is and isn't reversible in advance. This is a missed opportunity. For example, offering easy, Web-based reversibility for an opt-in e-mail newsletter, and making this reversibility visible, often increases conversion rates. That's because the user doesn't feel as if he or she is incurring too much risk, in terms of unwanted e-mails or wasted time. >> To Top

Satisfice: a hybrid word formed from satisfy and suffice, referring to the tendency of time-starved, information-overloaded users to select the first good-enough solution that crosses their path. Users often use satsificing as a triage strategy, based on the time and effort a more comprehensive search might entail. Coined by artificial intelligence pioneer Herbert Simon. >> To Top

Topsight: An informed vantage point that provides parallel insights into both the big picture and the way its component parts fit together to form the whole. Computer scientist David Gerlenter coined the term in his 1991 book, "Mirror Worlds: Or the Day Software Puts the Universe in a Shoebox," in which he called topsight "the most precious intellectual commodity known to man." The idea of topsight transcends the mutually exclusive, and mutually limiting, categories of top-down and bottom-up thinking. Enterprise Web-based applications can enable topsight by allowing users to navigate from a telescopic big picture view to a microscopic detailed view and back within a fluid, seamless user experience. >> To Top

Usage Expectation: An educated guess about how you plan to use a system, and how you expect the system will function. Often, there is a large gap between a system's intended use and a user's usage expectation. Usage expectations are often shaped by a user's cultural context. For example, in China, some users expect that Web-based software will offer built-in group collaboration tools, reflecting the collectivist work structure that has pervaded the country. >> To Top

User-Centered Design (UCD): An approach to Web design and development that advocates direct user input, early and often, into the process. UCD represents a Web-focused popularization, paricularly in the business community, of the HCI (Human-Computer Interaction) discipline. The term dates back to 1986, when cognitive psychologists Donald Norman and Stephen Draper coined the acronym UCSD (user-centered system design) because it matched the initials of their employer, The University of California at San Diego. >> To Top

User Experience (UX): Across the Interent industry, an important language shift is taking place, from the older GUI (graphic user interface) to the newer term, UX, short for User Experience. Why? Because GUI puts too much emphasis on the graphics, and too little emphasis on the user. Itís a kind of last-mile problem: no matter how much time and labor your company invests in the design and development of its Web site or enterprise application, the true value comes when a user understands and engages with the experience they see before their eyes. The real action isnít taking place on the screen -- it's taking place in the mind of your users. >> To Top

Visibility: Indicates whether you can easily see a particular element of the screen given the other items that surround it. Visibility is a delicate balancing act. For example, placing a headline in uppercase letters raises visibility. You're more likely to notice that there's a headline there. But when you zero in to actually read that headline, uppercase letters are harder to read than lowercase letters; added visibility has reduced readability. When deciding how visible or "loud" an item should be on a page, you have to make educated choices about what's most important to the user. >> To Top