Space Craft: Perceptual Aids for Cognitive Activity
Kevin Mullet, Macromedia Product Development
Seminar on People, Computers, and Design
Stanford University February 23, 1996
The effective use of space and spatial metaphors is a critical success factor in graphical user interface (GUI) design. Sadly, this is also an area that has been largely neglected by toolkit, framework, and application developers. Effective use of space is prohibitively difficult in modern GUI'; because the foundation layers of common software platforms provide little or no support for complex, expressive layouts (OSF/Motif with its Form and Frame widgets is one notable exception). Even worse, several familiar UI conventions such as the use of group boxes linking labels to controls or non-modular button widths that automatically match the length of their labels present severe problems for spatial parsing but have nevertheless become common by virtue of their availability in popular toolkits.
A coherent visual organization enhances not only the aesthetics of an interface design, but its usability as well. Because spatial information is available at the earliest stages of perceptual processing, displays with spatial structure that is both obvious and relevant can be used to enhance higher-level cognitive functions. Making the important contextualizing or relational information apparent at a glance helps users orient themselves, locate the information they need, and target or navigate efficiently. Spatial relationships, moreover, can make information displays easier to understand by revealing internal relationships more concretely and explicitly: the visual structure of a carefully crafted display will both reflect and reinforce the semantic structure of the underlying information.
Print designers have been acutely aware of the importance of space craft since the Futurist, Constructivist, and De Stijl movements of the early 20th century. Their pioneering experiments with active layouts, asymmetric typography, and other spatial interactions showed how parts of a composition exert forces on one another that can be controlled by the designer and used to influence perception of the resulting display. These influential movements form the foundation of modern graphic design, but their influence on user interface design has thus far been minimal, at least in the area of software tools and standard GUI environments (content-oriented multimedia has been somewhat more successful).
The focus of this talk is on layout issues in 2-dimensional spaces. We will briefly survey the growing popularity of 3d representations, but our emphasis will be on the application of effective spatial design in four key areas:
- Visual Coding
- Visual Structure
- Visual Representation
- System Design
We will see how spatial articulation can be used, in each of these areas, to simplify learning, enhance memory, and streamline problem solving. Numerous examples will show how coherent visual structure makes a menu easier to scan, a dialog easier to interpret, or a window easier to operate. We will also see how careful space craft can reduce the need for explicit labeling and make the interface more approachable for beginning users without sacrificing operational efficiency for advanced users. Finally, we will describe one very simple technique -- alignment of adjacent elements -- that can be applied fairly mechanistically to virtually any problem in GUI design. With just a little practice, this technique can be used to produce noticeable improvements in the visual structure and aesthetic quality of practically any product.
Kevin Mullet is the Product Designer for Macromedia's industry leading multimedia authoring and graphics production tools ( Director, Authorware, SoundEdit, FreeHand, xRes, Extreme 3D ) for the Macintosh and Windows environments. He is also the lead designer for the Macromedia User Interface - a set of presentation and interaction design standards created to unify suites of diverse applications in a series of task-focused, tightly-integrated digital design studios.
Previously Mr. Mullet was a Human Interface Engineer at Sun Microsystems, Inc., where he worked on advanced UNIX development environments in SunPro and on object-oriented desktop environments and productivity applications in SunSoft. He has extensive application design experience and is a leading expert on the OPEN LOOK Graphical User Interface. Prior to joining Sun, he was Senior Designer at Aaron Marcus and Associates - a Berkeley, CA based consulting firm specializing in systematic, information-oriented design for graphical user interfaces.
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