The Most-Cited Authors on Wikipedia Had No Idea

EACH TIME A volunteer editor adds a new fact to one of Wikipedia's over 44 million articles, they're required to citewhere they learned it. The nonprofit Wikimedia Foundation, which oversees the encyclopedia, became interested in what kinds of sources editors rely on the most. A recent studyconducted by the organization revealed something fascinating: A single academic paper, published by three Australian researchers in 2007, has been cited by Wikipedia editors over 2.8 million times—the next most popular work only shows up a little more than 21,000. And the researchers behind it didn't have a clue.

"Those numbers blew me away," says Brian Finlayson, one of the authors of the study and a retired geography professor at the University of Melbourne. "None of us had any idea about this. We didn't know Wikipedia collected this information or anything about it."

"It's a statistic that's hardly believable," says Thomas McMahon, a retired engineering professor at the same school and another co-author of the paper.

It starts to make more sense, though, when you consider the focus of the research. Over a decade ago, Finalyson, McMahon, and Murray Peel created an updated map of world climate, based on the work of Russian-German climatologist Wladimir Köppen. In 1884, Köppen published one of the first maps of weather patterns around the world. It broke Earth into major climate classifications, like tropical rainforest, desert, and savanna. For over a century, Köppen's map informed the work of researchers and students from nearly every discipline. If you want to contrast, say, how animals behave in deserts versus highlands, you'd turn to Köppen's map. It was taught in schools across the globe, and became regarded as one of the most widely used academic resources.

In the 1950s, German climatologist Rudolf Geiger updated Köppen's climate map, creating what is sometimes referred to as the Köppen-Geiger climate classification system. Then, for decades, it went largely unmodernized. At least until the researchers from the University of Melbourne came along.

Around 2005, McMahon, Finlayson, and Peel (a PhD student at the time) were researching how streams flowed in different parts of the world. Their studies required learning about rainfall, and collecting data on general climate patterns across different regions, in order to make comparisons. Over time, the academics noticed they had amassed an enormous amount of data about climate across Earth—enough to re-draw the map Köppen had developed a century earlier. So they decided to create and publish an updated version.

"There's nothing scientifically new in it, we simply used Köppen's classification and added new data to it and then drew a world map," says Finlayson. "The reason it's so widely cited is because it's useful, and I think that's the important point about it, it's not that we suddenly dropped into the system this brand new thing that had never been done before."

The researchers knew the map had the potential to be widely useful, so they specifically sought to publish it in an open-access journal where anyone could view it without needing to pay a fee. "Back in 2006/2007, Hydrological and Earth Systems Sciences was one of the few open-access journal options available to us, so we very happily submitted the paper to HESS," says Peel. While it was under review, he says, it began to draw the attention of Wikipedia contributors, like Jeroen van Riet Paap, a longtime Dutch editor who emailed Peel asking whether he could cite it.

On Wikipedia, the researchers' map serves as an important reference for nearly everything, from types of plants and animals to specific geographic regions as well as countries. Unlike some of the other most-used Wikipedia sources, like a catalog of fishesand a book about the history of Romania, the Australians' map is nearly universal. The articles that cite it also tend to be published in many languages, compounding the number of references. The resource is also widely popular elsewhere on the internet: Lonely Planet, a major travel guide publisher, uses it to provide general weather information for different parts of the world.

One caveat: Wikimedia's study was only able to track sources that had identifiers, meaning a DOI number for scholarly papers or an ISBN number for book editions. It's possible the Australians' climate map has been cited many more times, just without its associated DOI number. It's also possible something else may have been cited more times—but just doesn't have an identifier. The Wikimedia Foundation says its working on calculating what percentage of sources are referenced with and without their associated identifiers.

The Australian's climate map is also cited repeatedly in scholarly works across all sorts subjects, since climate can affect everything from biology to sociology. "The academic papers that we get cited in cover an enormous range of study areas, and that's because people are comparing sites across the globe in a whole range of disciplines," Finlayson explains. He receives an automated email every time the map is cited and says it can be funny to see where it's being used. "There was a publication done by veterinary scientists looking at the reproductive organs of female goats," he says. "That one is just stuck in my mind, but there are lots of things like that."

Learn more at WIRED

MediaElana Aliping