Stage 1. Identify design principles.
We identify domain-specific design
principles by analyzing the best hand-designed visualizations within a particular information domain. We connect this analysis with research on
perception and cognition of visualizations;
Stage 2. Instantiate design principles. We encode the design principles
into algorithms and interfaces for creating visualizations; and
Stage 3. Evaluate design principles.
We measure improvements in information processing, communication,
and decision making that result from
our visualizations. These evaluations
also serve to validate the design principles.
We have used this three-stage approach to build automated visualization design systems in two domains:
cartographic visualization and technical illustration. In the domain of
cartographic visualizations we have
developed automated algorithms for
creating route maps1, 3, 12 and tourist
maps of cities.
8 In the domain of technical illustration we have developed
automated techniques for generating
assembly instructions of furniture
and toys2, 9 and for creating interactive
cutaway and exploded-view illustrations of complex mechanical, mathematical, and biological objects.
11, 13, 14, 19
Here, we focus on articulating the
techniques we have used to identify
and evaluate the design principles
for each domain. These techniques
generalize to other domains, and applying our three-stage approach will
result in a better understanding of the
Figure 3. exploded views of complex
mathematical surfaces are designed
to reveal local geometric features (such
as symmetries, self-intersections, and
strategies people use to make inferences from visualizations.
stage 1. identify Design Principles
Design principles are prescriptive
rules describing how visual techniques affect the perception and cognition of the information in a display.
In some cases, they are explicitly outlined in books; for example, books on
photography techniques explain the
rules for composing pleasing photographs (such as cropping images of
people just below the shoulders or
near the waist, rather than at the neck
or the knees). Researchers have directly applied them to build a variety
of automated photo-manipulation algorithms (see the online appendix for
However, our experience is that design principles are rarely stated so explicitly. Thus, we have developed three
strategies for extracting and formulating domain-specific design principles:
( 1) analyze the best hand-designed visualizations in the domain, ( 2) examine prior research on the perception
and cognition of visualizations, and,
when necessary, ( 3) conduct new user
studies that investigate how visual
techniques affect perception and cognition.
Hand-designed visualizations. We
have found that a useful first step in
identifying design principles is to
analyze examples of the best visualizations in the domain. This analysis
is designed to find similarities and recurring patterns in the kinds of information the visualizations highlight, as
well as the techniques used to emphasize the information.
Consider the problem of depicting
the internal structure of complex mechanical, mathematical, anatomical,
and architectural objects. Illustrators
often use cutaways and exploded views
to reveal such structure. They carefully choose the size and shape of cuts,
as well as the placement of the parts
relative to one another, to expose and
highlight the internal structure and
spatial relationships between parts.
We have analyzed a large corpus of cutaways and exploded views to identify
the principles and conventions expert
illustrators commonly use to generate
11, 13, 14, 19 Our process for
FIGure 4. daVId Macaulay, the new way thInGs work
Figure 4. hand-designed “how things work” illustrations (a) use motion arrows and frame sequences to convey the motion and interactions
of the parts within a mechanical assembly. our system analyzes a geometric model (b) of a mechanical assembly to infer the motion and
interactions of the parts, then generates the motion arrows and frame sequences (c–d) necessary to depict how the assembly works.