[Editors] MIT: New tool measures clutter

[Patti Richards]

MIT News Office
Massachusetts Institute of Technology
Room 11-400
77 Massachusetts Avenue
Cambridge, MA  02139-4307
Phone: 617-253-2700
http://web.mit.edu/newsoffice/www

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MIT 'clutter detector' could cut confusion
New software tool measures visual clutter
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For Immediate Release
TUESDAY, AUG. 21, 2007
Contact: Patti Richards
Phone: 617-253-8923
Email: prichards at mit.edu

CAMBRIDGE, Mass.(08/21/2007)--A team of MIT scientists has identified 
a way to measure visual clutter. Their research, published Aug. 16 in 
the Journal of Vision, could lead to more user-friendly displays and 
maps, as well as tips for designers seeking to add an 
attention-grabbing element to a display.

The danger of clutter--especially on a visual screen--is that it 
causes confusion that affects how well we perform tasks. To that end, 
visual clutter is a challenge for fighter pilots picking out a 
target, for people seeking important information in a user interface, 
and for web site and map designers, among others.

"We lack a clear understanding of what clutter is, what features, 
attributes and factors are relevant, why it presents a problem and 
how to identify it," said Ruth Rosenholtz, principal research 
scientist in MIT's Department of Brain and Cognitive Sciences (BCS) 
and the paper's lead author.

The fact that one person's clutter is the next person's organized 
workspace makes it hard to come up with a universal measure of 
clutter. Rosenholtz and colleagues modeled what makes items in a 
display harder or easier to pick out. They used this model, which 
incorporates data on color, contrast and orientation, to come up with 
a software tool to measure visual clutter.

To be useful, such a tool has to capture the effect of clutter on 
performance.  In their paper, Rosenholtz and her colleagues--MIT BCS 
graduate student Yuanzhen Li and BCS undergraduate Lisa 
Nakano--tested the influence of clutter on searching for a symbol in 
a map, like an arrow indicating "you are here."  They found good 
correlation between the time it takes to find a symbol in a map and 
the amount of clutter according to their measure.

In earlier work they also showed that their clutter detector 
correlates well with human subjective judgments of clutter. In that 
case, the team asked 20 people to rank 25 maps of the United States 
and San Francisco in order from most cluttered to least cluttered. 
The maps ranged from a gray and green map of the 50 states to a San 
Francisco Bay area map overlaid with lines, words and colors.

Although there was a fair bit of disagreement among the people being 
tested about what constituted clutter, when the researchers compared 
results from their clutter measure to those of their human subjects, 
they found a good correlation.

Rosenholtz next plans to offer this visual clutter tool, as well as 
other tools developed in her lab, to designers as part of a user 
study.  She hopes to learn what insights designers get from knowledge 
of how a user will likely perceive their designs, and how best to 
present this information to the designers. 

Rosenholtz provides free software written in MATLAB to anyone 
interested in generating color and contrast "clutter maps" to gauge 
the clutter level of a display. The tool is available at 
http://web.mit.edu/rruth/www.

This work was supported by the Office of Naval Research and by the 
National Science Foundation.
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