Date: Wed, 8 Nov 2000 20:00:26 PST From: Eric Saund <[EMAIL PROTECTED]> Subject: Visual perception of document images Controversy has arisen over a ballot in Palm Beach County, Florida that many people have claimed is misleading and ambiguous in its design. By at least one news report, the local election commissioner claims "There is nothing wrong with this ballot". Clay Roberts, director of Florida Department of Elections, is quoted to have said, "The ballot is very straightforward. You follow the arrow, you punch the location". I am a visual perception scientist at the Xerox Palo Alto Research Center. I study visual perception of document images: How do people's brains connect the image on their retinas to the meaning formed in their minds. Spatial layout is critical. In my judgement, this ballot is visually ambiguous. There are two valid ways of parsing this image. One way is by following the arrows from candidates names to punch holes. The arrows are rather small and not clearly shaped, and they have little numbers next to them that add to the visual clutter. It would be perfectly natural for your visual system to treat the arrows as visual texture, and just filter it out. A second valid way of parsing this image is by reading order. When we open a book we don't take it in all at once. We direct our attention first to the left page, then move our eyes left to right, top to bottom. Then we look at the right page. It would be perfectly natural for a person to read down the left page, see the candidate they want to vote for, then stop reading. Now they switch tasks, to finding which hole to punch. One way of doing this is by noticing and following the arrow. Another way is by keeping a mental count. If you want to vote for the second entry, count down two holes. You probably couldn't vote for the sixth ballot entry this way, but the second, sure. Why didn't they catch this before? If you're inspecting the ballot to proofread it, making sure no one's name is spelled wrong, then you might not notice the layout problem. When you know the intent of the ballot layout, then your top-down processing can influence your perception and resolve the ambiguity automatically so it all looks like it makes sense. But to someone seeing this image for the first time, in the polling booth, they have to figure it out in the moment. It takes a different kind of looking to notice the layout problem. It's something that good graphic designers do intuitively. Seeing is an automatic, unconscious process. We are not aware of all the assumptions our minds make when we view a scene. It is perfectly plausible that a visually ambiguous ballot could get through the inspection process. I would not fault anyone for punching the wrong hole on this ballot. This ballot is poorly designed. -Eric Saund -------------------- Eric Saund, Ph.D. Xerox PARC 3333 Coyote Hill Rd. Palo Alto, CA 94304 (650) 812-4474 (650) 812-4334 (fax) [EMAIL PROTECTED] http://www.parc.xerox.com/saund ======================================= Eric Saund is a research scientist at Xerox PARC. He is an authority on the architecture of human visual perception and its consequences for the design of documents. Here he analyzes the claims that the disputed presidential election ballot in Palm Beach County, Florida is misleading and ambiguous. You can see images of the disputed ballot in many places on the net, including these: http://www.sun-sentinel.com/elections/palmbeachballot.htm http://cnews.tribune.com/news/image/0,1119,sunsentinel-nation-82373,00.html Here is another analysis by Dan Bricklin: http://www.bricklin.com/log/ballotusability.htm =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
