Zebra striping—also known as candy striping or half-shadow—is the application of faint shading to alternate lines or rows in data tables or forms. Examples of websites that use zebra striping include the currency site XE, the CIA World Factbook, and Monster.com. Zebra striping on the web is actually a carryover from print days: one of the first mentions of the technique appeared in 1961 .
Many believe that zebra stripes aid the reader by guiding the eye along the row. However, despite being in use in both paper and electronic mediums for almost half a century, there is practically no evidence that it actually assists users in this way. In June and July 2007, I conducted an extensive review of sources such as the International Association of Paper Historians, the Business and Forms Management Association, and the IEEE Annals of the History of Computing, but found absolutely no information on the origins of or rationale behind zebra striping.
I recently conducted a study into the helpfulness (or lack thereof) of zebra striping—the shading of alternate rows in a table or form. The study measured performance as users completed a series of tasks and found no statistically significant improvement in accuracy—and very little statistically significant improvement in speed when zebra stripes were implemented.
These results were a surprise to many readers of the corresponding article, published in A List Apart in May, 2008. I think it’s fair to say that the vast majority of us, myself included, expected to see that zebra striping helped a lot.
Because of these surprising results, I decided to conduct two more studies into the value of zebra striping. These studies aimed to test design elements deliberately excluded from the first study, and to address some of the issues raised by the results of the first study.