Overview of Graphical User Interfaces

Article excerpt

There has been a strong move in libraries from traditional card catalogs to Online Public Access Catalogs (OPACs). Access to these catalogs has been through the use of non-programmable, or "dumb" terminals. These terminals are now being replaced by microcomputers as front ends to library and other host systems. Computer technology, especially microcomputers, and telecommunications are therefore an integral part of information access and library services, and these technologies are continually advancing.

The capability of microcomputers to support graphics and the increasing speed of the chip technology provide a powerful base for more sophisticated design of the OPAC. One design change to the OPAC being investigated is that of a graphical user interface, or GUI. A user interface created using GUI concepts provides consistent access between applications. It can provide easy-to-use access to the library holdings, as typical of a traditional OPAC, but also consistent access to a variety of information services available on the host.

The OPAC Screen: A History

The first OPACs were simply an electronic version of the traditional card catalog and"...consisted of machine-readable records that represented the library's bibliographic holdings of books and journals...."[1] This was true up through the early 1980s. In some cases, commands were entered using a keyboard to initiate a search and obtain results, which were displayed in very simple formats -- much as many online database systems still do today. Other systems used menu screens to make such tasks easier to accomplish. The term user-friendly at that time meant that access to information was through simple menu screens by picking a number or letter from a menu of choices. This was easier to do than trying to remember the commands. But these were not necessarily always easy to use and often required the user to navigate back through menus in order to exit. This constant navigation was not very effective, efficient, or "user-friendly."

It wasn't until the late 1980s and early 1990s that graphical interfaces to online catalogs emerged. As noted by Freivalds and Carson,[2] the advancements in technology and telecommunications have enabled libraries to replace the "dumb terminals" with microcomputer workstations "capable of sound and image processing," providing new ways of extending the OPAC. A graphical interface can help orient the user to these extensions.

But, what exactly is a graphical user interface? A graphical user interface, or GUI (pronounced "gooey"), is typically thought of as a combination of windows with pull-down menus, icons (pictures to represent things or ideas), and a pointing device such as a mouse or trackball to manipulate information. It is perceived by many people to be easier to use than the more traditional commands and menus used in many computer applications today. Examples of some software available which have a form of GUI include: Apple Computer's Macintosh operating system, Microsoft Windows 3.0 for DOS, Presentation Manager for IBM OS/2, and the combination of an X-Windows System with either Open Look (from AT&T and Sun Microsystems) or Motif (Open Software Foundation) for Unix platforms.[3]

OPAC Front-End Design

Joseph Matthews points out in his article on design of online catalogs that "As online catalogs proliferate and users move from system to system it becomes crucial that the user of the online catalog be presented with screens that are relatively similar in layout and content ... familiar screens mean less time will be needed to (re)learn the use of an online catalog in a variety of library settings."[4] He further points out important characteristics which should be incorporated into the screen design, such as consistent display formats and labeling.[5] Although these statements are in reference to display of bibliographic information on non-programmable terminals, they can apply to graphical screen design as well. …