Wikipedia entries on politically controversial scientific topics - global warming, acid rain and evolution - can be unreliable according to a new study.
Researchers analysed Wikipedia edit histories for three politically controversial scientific topics (acid rain, evolution, and global warming), and four non-controversial scientific topics (the standard model in physics, heliocentrism, general relativity, and continental drift).
"Wikipedia's acid rain entry receives near-daily edits, some of which result in egregious errors and a distortion of consensus science," said Dr Gene E Likens, President Emeritus of the Cary Institute of Ecosystem Studies and a Distinguished Research Professor at the University of Connecticut.
In an effort to see how Wikipedia's acid rain entry compared to other scientific topics, Likens partnered with Dr Adam M Wilson, a geographer at the University of Buffalo.
Using nearly a decade of data, Likens and Wilson teased out daily edit rates, the mean size of edits (words added, deleted, or edited), and the mean number of page views per day.
While the edit rate of the acid rain article was less than the edit rate of the evolution and global warming articles, it was significantly higher than the non-controversial topics, researchers said.
Across the board, politically controversial scientific topics were edited more heavily and viewed more often.
"Wikipedia's global warming entry sees 2-3 edits a day, with more than 100 words altered, while the standard model in physics has around 10 words changed every few weeks," Wilson noted.
"The high rate of change observed in politically controversial scientific topics makes it difficult for experts to monitor their accuracy and contribute time-consuming corrections," he said.
"As society turns to Wikipedia for answers, students, educators, and citizens should understand its limitations when researching scientific topics that are politically charged.
"On entries subject to edit-wars, like acid rain, evolution, and global change, one can obtain - within seconds - diametrically different information on the same topic," said Likens.
Researchers note that as Wikipedia matures, there is evidence that the breadth of its scientific content is increasingly based on source material from established scientific journals.
They also note that Wikipedia employs algorithms to help identify and correct blatantly malicious edits, such as profanity.
But in their view, it remains to be seen how Wikipedia will manage the dynamic, changing content that typifies politically-charged science topics.
The study was published in the journal PLOS ONE.