Bringing Design to Software
© Addison-Wesley, 1996
Profile 2. The Alto and the Star
Profile Author: Terry Winograd
In 1970, the Xerox Corporation established the Palo Alto Research Center (PARC), to invent the future of the electronic office. In PARC's first decade, a stream of innovations emerged that set the stage for today's computer industry. Among other technologies, laser printing, local-area networking, and desktop publishing software were first developed at PARC. Many of the prominent companies in the computing industry, such as 3COM, Adobe, and Apple Computer were started or were heavily influenced by PARC graduates.
PARC's most notable innovation was the personal computer, which grew out of earlier concepts by Alan Kay for what he called a reactive engine and a Dynabook . The progenitor of the modern personal computer, the Alto, was developed in 1972 by Kay's Learning Research Group (LRG) and a number of researchers in PARC's Computer Systems Laboratory (CSL), under the direction of Robert Taylor. Just as the Model-T contained the fundamental elements of a modern automobile, the Alto included the central elements of today's personal computer: a bitmapped graphic display, which enabled it to display text in multiple fonts, combined with graphics; a mouse as a pointing device; removable magnetic storage; and an operating system designed for a single user who alternates among multiple applications. Although the Alto's cost at the time was high (at standard industry markup, it would have sold for more than $75,000), the PARC strategy was to act as though the Alto was a personal computerto put one on every desk and to see what people would do with it.
The result of this bold strategy was a proliferation of experimental software for writing, drawing, communicating, teaching, and computing in many domains. The Smalltalk language and programming environment, developed by Kay's LRG, pioneered uses of the graphic interface. Other software developed in CSL included the Bravo text editor, which developed many of the sophisticated features of today's word processors and was the predecessor of Microsoft Word; Draw and Markup, the ancestors of MacDraw and MacPaint, and the many drawing programs that later followed their lead; and programs that made it possible for personal-computer users to make use of networked facilities for file storage and laser printing.
The Xerox Star was born out of PARC's creative ferment, designing an integrated system that would bring PARC's new hardware and software ideas into a commercially viable product for use in office environments. The Star drew on the ideas that had been developed, and went further in integrating them and in designing for a class of users who were far less technically knowledgeable than the engineers who had been both the creators and the prime users of many PARC systems (one of PARC's favorite mottoes was "Build what you use, use what you build.") As David Liddle describes in Chapter 2, the Star designers were challenged to make the personal computer usable for a community that did not have previous computer experience.
From today's perspective, the Star screen (Figure 2.4) looks rather unremarkable, and perhaps a bit clumsy in its graphic designa boxy model-T when compared to the highly styled look of today's Taurus or Jaguar. What is notable from a historical perspective, of course, is how much the Star does look like current screens and how little it looks like the character-based and vector-drawing screens that preceded it.
Figure 2.3 [in the book, not the exact one here] The Star (Viewpoint) screen image The Star pioneered the now-familiar constellation of icons, moveable scrollable windows, and intermixed text and graphic images. The widely used graphic user interfaces (GUIs) of today are all variants of this original design. (Source: Reprinted by permission from Jeff Johnson et al. Xerox Star, a retrospective. IEEE Computer 22:9 (September, 1989), p. 13.)
The visible mechanisms on the Star display were backed up with a set of design principles that grew out of a user-oriented design methodology and by a great deal of empirical testing, as described by Liddle in Chapter 2. Several principles were central to the Star design:
1. Direct manipulation. The core concept that distinguished Star (and other Alto programs) from the conventional computer interfaces of their time was the use of a bitmapped screen to present the user with direct visual representations of objects. In the Star'sdesktop metaphor, documents, printers, folders, collections of folders (file drawers and cabinets), in and out boxes, and other familiar office objects were depicted on the screen. To print a document, for example, the user could point (using the mouse) to the icon for the document and the icon for the printer, while using a key on the keyboard to indicate a Copy operation.
2.WYSIWYG (what you see is what you get). In previously available programs for producing sophisticated graphical outputsuch as drawings or page layout with multiple fontsthe user created and edited a representation that looked like a programming language, and then compiled the resulting program into a visible form. Alto programs pioneered a new style that Star unified, in which the user works directly with the desired form, through direct manipulation. The user makes changes by operating on a direct representation of what will appear on the printed page. As shown in Figure 2.3, the Star user could intermix text, tables, graphs, drawings, and mathematical formulas. In fact, most of the popular microcomputer applications of today have not yet reached the degree of integration that Star offered more than a decade ago.
3. Consistency of commands. Because all Star applications were developed in a unified way by a single development group, it was possible to adhere to a coherent and consistent design language (see Chapter 4 for a discussion of design languages). The Star keyboard embodied a set of generic commands, which were used in a consistent way across all applications: Move, Copy, Delete, Open, Show Properties, and Same (copy properties). Evoking one of these commands produced the same behavior whether the object being moved or copied, for example, was a word of text, a drawing element, or a folder of documents. Through the use of property sheets (Figure 2.1), the user could manipulate the aspects that were specific to each element, such as the font of a text character, or the brush width of a painted line. The Open command was the basis for applying a technique of progressive disclosureshowing the user only the relevant information for a task at hand, and then providing a way to reveal more possibilities as they were needed.
In addition to these three key concepts, many specific design features made the Star unique, including its attention to the communicative aspects of graphic design, its integration of an end-user scripting language (CUSP), and its underlying mechanisms for internationalizationfrom the very beginning, Star versions were developed in several languages, including non-European languages with large character sets, nonleft-to-right orthography, and so on.
Some of the aspects that led to the Star's design quality may have also hampered its commercial successin particular Xerox's dependence on development groups within a single company to produce all the applications software. But the result was one that supports Liddle's assertion that "In some aspects, I still think that Star was a great advance over its successors."
David Canfield Smith, Charles Irby, Ralph Kimball, Bill Verplank, Eric Harlslem. Designing the STAR user interface.Byte 7:4 (April, 1982), 242282.
William Bewley, Teresa Roberts, David Schroit, and William Verplank. Human factors testing in the design of Xeroxs 8010 "Star" office workstation. Proceedings of CHI'83, New York: ACM, 1983, 7277.
David Liddle, Design of the Conceptual Model, in Bringing Design to Software, Addison-Wesley, 1996, 17-31.
Additional Source Materials (not in BDS as published)
Bruce Damer's Personal Histories of the Desktop User Interface: A Retrospective of the Xerox Alto, Star 8010 System and Elixir Desktop: http://www.damer.com/pictures/elixir/products/star.html
Lawrence Miller and Jeff Johnson, The Xerox Star: An Influential User Interface Design, in Rudsill, Lewis, Polson, and. McKay, (eds.) Human-computer Interface Design: Success Stories, Emerging Methods, and Real-world Context.(1996). 70-100.
Bill Verplank, Graphic challenges in designing object-oriented user interfaces, in Martin Helander (ed.), Handbook of Human-Computer Interaction, Elsevier, 1988 (First edition), 365-376.
Video: Xerox Star Interface: An Overview [Xerox], SIGGRAPH Video Review Issue 56 - CHI '90 Techincal Video Program
Video: The Final Demonstration of the Xerox 'Star' Computer, 1981. Xerox PARC, June 17, 1998 (2 tapes, TRT 1:59:00 + 21:30).