Wikipedia’s mission is to allow everyone to share in the sum of all knowledge. Wikipedia is in its twentieth year, and it has been a success in many ways. And yet, it still has large knowledge gaps, particularly in language editions with smaller active communities. But not only there – did you know that only a third of all topics that have Wikipedia articles have an article on the English Wikipedia? Did you know that only about half of articles in the German Wikipedia have a counterpart on the English Wikipedia? There are huge amounts of knowledge out there that are not accessible to readers who can read only one or two languages.
And even if there is an article, content is often very unevenly distributed, and where one Wikipedia has long articles with several sections, another Wikipedia might just have a stub. And sometimes, articles contain very outdated knowledge. When London Breed became mayor of San Francisco, nine months later only twenty-four language editions had listed her as such. Sixty-two editions listed out-of-date mayors – and not only Ed Lee, who was mayor from 2011, but also Gavin Newsom, who was mayor from 2004 to 2011, and Willie Brown, who was mayor from 1996 to 2004. The Cebuano Wikipedia even lists Dianne Feinstein, who was mayor from 1978 to 1988, more than a decade before Wikipedia was even created.
This is no surprise, as half of the Wikipedia language editions have fewer than ten active contributors. It is challenging to write and maintain a comprehensive and current encyclopedia with ten people in their spare time. It cannot be expected that those ten contributors keep track of all the cities in the world and update their mayors in Wikipedia. In many cases those contributors would prefer to work on other articles.