Understanding user interface design rules - Part 2: System vocabulary and risk

To reduce the time it takes for people to master your application, Web site, or appliance, so that using it becomes automatic or nearly so, don't force them to learn a whole new vocabulary. Chapter 4 explained that familiar words are easier to read and understand because they can be recognized automatically. Unfamiliar words cause people to use more conscious decoding methods, which consumes scarce short-term memory resources and thereby lowers comprehension.

Unfortunately, many computer-based products and services present users with unfamiliar terms from computer engineering - often called "geek speak" - and require them to master those terms (see Fig. 11.6). Why? Operating a stove doesn't require us to master terminology about the pressure and chemical composition of natural gas, or terminology about the production and delivery of electricity. Why should shopping on the Web, sharing photographs, or checking email require us to learn geek speak such as USB, TIFF, or broadband? But in many cases, it does.

Some examples of interactive software systems using unfamiliar terminology:

• A development team was designing a video-on-demand system for schoolteachers to use in classrooms. The purpose of the system was to allow teachers to find videos offered by their school district, download them, and show them in their classrooms. The developers' initial plan was to organize the videos into a hierarchy of "categories" and "subcategories." Interviews with teachers showed, however, that they use the terms "subject" and "unit" to organize instructional content, including videos. If the system had used the developers' terminology, teachers who used it would have to learn that "category" meant "subject" and "subcategory" meant "unit," making the system harder to master.

• Continental Airlines' Web site displays several error messages that speak "geek" (see Fig. 11.7). Most are attempts to tell the Web site user about a problem, but because they use an unfamiliar jargon, few users understand what the site is saying and so are unsure what to do. Such error messages are more appropriate for reporting the problem to system engineers. Error messages like these should either be rewritten in terms users understand, or they should be displayed to the Web site administrators who monitor the operation of the site rather than to the users.

• Windows Media Player sometimes displays error messages that use familiar terms in unfamiliar, "geeky" ways (see Fig. 11.8). The error message in the figure is referring to the state of the software, but the average Media Player user is likely to interpret it as referring to the state in which he or she lives.

In contrast to these examples, Southwest Airlines' Web site tries to prevent errors from occurring, but when they do occur, it explains the problem using task-focused, familiar language (see Fig. 11.9).