From middle school to college, students the world around use Wikipedia as a resource — much to the dismay of their teachers. However, Wikipedia is a resource used by people everywhere, including teachers and researchers. But is it actually accurate? Or rather, how accurate is Wikipedia?

The wisdom of the crowd

Both the blessing and the curse of Wikipedia is that everyone can edit it — that means that a massive amount of articles can be written and managed thanks to the countless work hours put in by thousands of people — but it also means that inaccurate information can easily sneak in articles because thousands of people edit it. However, Wikipedia is not the free-for-all some people make it out to be.

Wikipedia carries the general disclaimer that it can be “edited by anyone at any time,” but there are also editors that keep an eye on things, and in time, Wikipedia has developed a system that is remarkably efficient, given the large number of volunteers and the low number of editors.

But this still doesn’t answer just how accurate Wikipedia is. 

Curiously enough, there’s a Wikipedia page on the Reliability of Wikipedia, but understandably, that shouldn’t really be as proof here. So instead, let’s look at some studies.

In 2014, a group of German researchers set out to test that and see just how accurate Wikipedia really is.

“[The] lack of a formal editorial review and the heterogeneous expertise of contributors often results in skepticism by educators whether Wikipedia should be recommended to students as an information source. In this study we systematically analyzed the accuracy and completeness of drug information in the German and English language versions of Wikipedia in comparison to standard textbooks of pharmacology”, researchers write.

Image via Wiki Commons.

The English Wikipedia seems like a good place to start since it is by far the largest and most active. The researchers analyzed articles on drugs, drawing every piece of relevant information, as well as references, revision history, and readability.

Their conclusion is that the accuracy of drug information on Wikipedia was 99.7%±0.2% when compared to the textbook data. However, even though the articles were very accurate, they weren’t fully complete — they didn’t treat the topics in an exhaustive way. Scientists rate the completeness of articles at 83.8±1.5%. However, completeness had a huge variation, ranging between 68.0% and 91.0%.

The researchers interpret the results as being very accurate, but not always complete. Essentially, Wikipedia is a good place to get accurate information (at least on this particular topic), but not a good place to get the whole information — although it’s noteworthy that it always provides over two-thirds of the whole story. Furthermore, from the drug information missing in Wikipedia, 62.5% was rated as didactically non-relevant in a qualitative re-evaluation study.

This is crucial, especially in areas that change a lot, such as pharmacology. The fact that you have this huge resource from which you can draw massive amounts of information is remarkable. The fact that it is open source, ad-free, community-driven (though moderated), and still manages to have an almost perfect accuracy is simply amazing. Still, the study only looked at drugs, which may not be representative for the entire Wikipedia.

More studies on Wikipedia’s Accuracy

Another study from 2005, this time published in Nature, compared the accuracy of a small number of articles (42) on scientific topics compared to Wikipedia and Encyclopaedia Britannica (which is traditionally considered more accurate). The articles were compared by anonymous academic reviewers, just like in scientific papers. Wikipedia had 4 errors or omissions, while Britannica had 3; Wikipedia had 4 serious errors, the same as Britannica. All in all, the study concluded that “Wikipedia comes close to Britannica in terms of the accuracy of its science entries”, although the articles on Wikipedia were found to be more “poorly structured”.

An important study on Wikipedia’s accuracy was carried out in 2014, noting that because of its comprehensiveness and because there are large differences between popular pages and less popular pages (and similarly, differences between languages), it’s hard to draw any definite conclusions. 

“Wikipedia articles improve in quality as long as they are supported by a balanced community of new and experienced, highly participative editors with shared language facilitating their cooperation,” the researchers concluded in the study.

The importance of how often an article is updated was highlighted by another study from 2014, which followed Wikipedia pages about 22 prescription drugs to determine if they had been updated to include the most recent FDA safety warnings. Some were, and very quickly — 41% of them were updated within two weeks of the warming. Another 23% were updated more than two weeks later. However, the remaining 36% had not been updated to include the warning one year later. This yet again highlights that highly participative articles tend to be more accurate.

The bottom line

Ultimately, for a collaborative project, Wikipedia has found a remarkably efficient model. Your professors may hate it, but it’s a good source of information for most things — actually, it’s a great source of information for most things.

Sure, the failures of Wikipedia are spectacular: like that time a  17-year-old student added an invented nickname to the Wikipedia article on the Brazilian coati, calling them “Brazilian aardvarks”, a nickname that stuck for six years and was propagated by hundreds of websites, several newspapers, and even a few books published by university presses; or that time a bored Chinese housewife created a compelling but fake history of medieval Russia. Sure, some pages are used specifically to disinform, and some politicians and companies have tried to use Wikipedia for their own advantage. There’s also the occasional vandalism, and there are still a lot of pages that aren’t maintained properly. But at the end of the day, it’s remarkably good; not perfect, but usually very good — and it’s getting better.

If you want to use Wikipedia for some documentation of scientific research, the best thing to do is to follow the original sources: Wikipedia typically lists original sources, and while you shouldn’t always trust Wikipedia as a primary source, you can try and follow it to find the actual primary sources of information.