Wikipedia is a treasure trove of the information age, albeit one with a generous sprinkling of counterfeit loot.

With more than 15 billion monthly pageviews from August 2015 to August 2016, Wikipedia is a titan of online information. Fact-checkers are starting to interact with the Wikimedia Foundation to address the accuracy of its entries — and have found a receptive audience.

The latest example is a Wikipedia "edit-a-thon" organized by Brazilian fact-checking site Lupa in partnership with investigative journalist outfit Abraji. Inspired by a prior exercise by Full Fact in the United Kingdom, the edit-a-thon dedicated a group of people to improving the accuracy of selected entries.

Seventy journalism students applied to take part in the edit-a-thon, held during the annual Piauí journalism Festival. The 16 who were selected met for four-hour sessions from Oct. 7 to 9.

After an introduction from Wikimedia on how to introduce edits and one from Lupa on the fact-checking process, the edit-a-thon focused on pages related to power, the overall theme of the Festival. The pages they settled on were biographies of the outgoing mayors of Rio de Janeiro and São Paulo, Eduardo Paes and Fernando Haddad.

Despite the fact that the two are nationally relevant political figures, the students found some significant inaccuracies. Paes' page, for instance, claimed that the mayor was a lawyer, but there is no record of him in the Brazilian Bar Association.

The students made a total of nine edits on the page of Paes and 10 on Haddad. Not all of these were fixing mistakes, though. Several of the edits confirmed the information available but provided a more authoritative source to back it up.

All edits made to the two pages were catalogued by Lupa here.