Library Journal "Digital Libraries" Columns 1997-2007, Roy Tennant
Please note: these columns are an archive of my Library Journal column from 1997-2007. They have not been altered in content, so please keep in mind some of this content will be out of date.
User Interface Design: Some Guiding Principles
Until the last few decades, the user interface to the library had long remained relatively unchanged. For decades, the only changes in the card catalog were minor tweaks in production techniques (from cards written in "library hand" to ones produced by computer). From grade school, library users became accustomed to the interface, and it changed not at all or very little (say, from Dewey Decimal to Library of Congress Classification) for the rest of their lives. Now user interfaces vary significantly from library to library, and even within a library, from library holdings to CD-ROM databases to web resources. Why such variation? Of course, there are different kinds of resources or different types of information. But good user interface design remains more art than science. The few "rules" can be successfully broken at various times and in various ways, although most rule breakers are unsuccessful. Also, designers honestly disagree about how best to make systems user-friendly. In the end, one person's great interface may be, unfortunately, another person's nightmare. System designers cannot use such difficulties to ignore their responsibility to design usable systems. Nor should they think that once a design is created, their work is done. A good user interface will evolve over time, as an organization learns about its shortcomings or becomes aware of new techniques or technologies. Guiding principles Without formal rules, guiding principles should always be considered but need not be slavishly followed for all audiences or purposes. The ones below are not the only principles to consider, just some basic ones from my own experience and that of others. The resources identified (below) offer more suggestions. To every element a purpose. Alternatively: be thankful for everything you can throw away. Because there is no more valuable "real estate" than space on a computer monitor, do not needlessly waste space nor allot it to items of little or no importance. If something is on screen, it must serve a useful purpose. This doesn't mean you can't use images or other embellishments; just avoid gratuitous ones. Avoid inconsistency. Few things will frustrate users as quickly as an inconsistent user interface. Do not move things around on the screen from page to page. Do not change what you label the same thing. And religiously follow whatever navigation scheme you devise. Strive for efficiency. In a web interface, users must follow particular "click trails" to accomplish certain tasks. Make that trail as short and as productive as possible, given other important considerations and constraints. Make every click count, and every screen appreciated. Support multiple users and multiple purposes. One truism concerning user interface design is that there is no single user. Therefore, any design must account for the diversity of users and their diversity of purposes, which may change over time. Talk to your users. The best way to discover how users like your system is to ask them. That "asking" can include focus groups, surveys, polls, and informal conversations. Methods that are always available (such as links from web pages) will encourage ongoing user feedback. Get help. Few individuals can ably handle all elements of a user interface design project. Be aware of your strengths, but acknowledge your shortcomings. Fill in for your lack of knowledge or experience by signing on additional talent. If you can't hire help, use internship or community service programs, or local volunteers. Choose labels wisely. Jargon should be avoided in most user interfaces (unless obfuscation is your goal). Beyond that, make sure labels are readily understandable to your user groups. And, as said above, avoid inconsistency. Do not introduce a new way of working when a familiar one will do. For example, programs for playing music on a computer often borrow features from a stereo system, with similar readouts, buttons, and functionality. Keep such nonvirtual examples in mind. Introduce a new way of working when it is clearly better. The familiar way is not always the most efficient or effective. If a new metaphor is clearly better, don't shrink from it simply because it requires users to learn it. You may be establishing a new model. Good examples One of the best ways to learn about good design is to look at other web sites. For instance, the Multnomah County Library site presents a lot of information in a straightforward and visually pleasing way. Notice how color is used to group similar choices on the main menu, making it easier to notice related items. For an academic audience, the University of California, Irvine, site presents a lot of information but never leaves you feeling lost. The techniques include context-specific navigation and persistent menu bars, To look at more library web sites, visit Libweb. Resources User interface expert Jakob Nielsen, formerly with Sun Microsystems, now consults, speaks, and writes on web usability issues. His online periodical, "The Alertbox," archived back to 1995, is a must-read. For a brief and useful review of user design considerations (albeit aimed mainly at software developers), see "User Interface Design Tips and Techniques." The "User Interface Design Bibliography" will point you to a rich selection of print resources, with a list of web sites at the end. The "Human-Computer Interaction Bibliography" is a huge resource of about 20,000 entries. A good overall book on effective web design (increasingly the interface of choice to library resources of all types) is Information Architecture for the World Wide Web by Louis Rosenfeld and Peter Morville, both librarians and consultants. Remember the interface Few things are as important to a digital library project as effective user interface design. Unfortunately, it is often a secondary consideration. To avoid the pitfalls of a bad design, do your homework, look at what others have done, get help, and talk to your users. LINK LIST The Alertbox: Current Issues in Web Usability http://www.useit.com/alertbox/ Human-Computer Interaction Bibliography http://www.hcibib.org/ Information Architecture for the World Wide Web http://www.oreilly.com/catalog/ infotecture/ Libweb http://sunsite.berkeley.edu/Libweb/ Multnomah County Library http://www.multnomah.lib.or.us/lib/ UC-Irvine Library http://www.lib.uci.edu/ User Interface Design Tips and Techniques http://www.ambysoft.com/ userInterfaceDesign.html User Interface Design Bibliography http://world.std.com/ ~uieweb/biblio.htm