Gender gaps and geographical imbalances on Wikimedia are already well-researched. Our focus is a cultural gap which does not correspond exactly to geography. For example, on the English Wikipedia, List of sculptors is 99% Western, despite sculpture being common to many different cultures, Lists of painters by nationality is around 75% European, and List of contemporary artists is 80% European. Many countries with especially rich artistic traditions, such as Libya and Mali, do not even have dedicated articles about their art (in the same way as there exist exhaustive articles such as French art or Greek art). The English Wikipedia's Level-4 Vital Article list for visual artists currently includes six from non-Western cultures, out of 124 articles.
On Commons, the Gallery of Non-Photographic Media – Religious Art showcases ninety pieces of art relating to Christianity, alongside eight images for Buddhism, five for Judaism, five for Hinduism, and three for Paganism. Islam, with around two billion followers worldwide, has three examples of religious art (two of which we've uploaded).
It's unequivocally a good thing that Wikimedia projects make so much knowledge about art freely available. Our concern is that its overwhelming focus on the Western canon gives readers a misleadingly narrow picture of visual art and its role in human cultures. It's great that there are extensive articles about John Constable or the Bayeux Tapestry in English; we just want similar recognition for the artists or works from different cultures that are at least as important to those cultures as Constable is to British culture: Shibata Zeshin in Japan, or Raden Saleh in Indonesia, for example.
The Wikidata project Sum of All Paintings is extremely impressive in how it has drawn together details of more than 600,000 paintings from thousands of catalogues. While praising it, we have to be aware that a focus on paintings, usually by named artists, is itself a kind of bias towards European culture. The most celebrated art within another culture might be textile art, architectural features, or calligraphy; we should document these as well.
For our quantitative research, we consulted books and art experts to build lists of artists and works from cultures outside the Western canon. These were compared against lists of Western artists and works drawn from the Vital Articles lists on the English Wikipedia. Most of the non-Western masterpieces had no dedicated representation at all on the Wikimedia projects (though they might be mentioned in artists' biographies). So the main part of our research calculated the ratio of coverage of the two sets of artists (in terms of bytes of text, Commons files, or Wikidata statements). This measure is independent of the size of the Wikipedia, and allows us to place each Wikimedia project on a spectrum from "Western" to "global" for the visual arts.
Taking all languages in aggregate, Wikipedia gives seven times as many bytes of coverage to the Western artists as the artists from other cultures. Wikidata's coverage is more even, with four times as many statements for Western artists. Commons has 21 times as many files relating to Western artists. The individual language versions of Wikipedia formed a spectrum with Indonesian, Punjabi, and Bengali among the more "global" while Italian, Polish and Serbian were amongst the most "Western". The big surprises: English Wikipedia is one of the most "global" (a ratio of 4) and Thai Wikipedia the most focused on Western art (a ratio of 40).
Like other biases on Wikipedia, this cultural imbalance results from a combination of factors outside and inside the project: the availability of sources and images as well as the interests of volunteers. So improving the situation involves both external outreach and on-wiki activity.
The external factors include the availability of reliable sources in the appropriate language, and of digital images of the appropriate content. We had seen that Commons in particular has a heavy bias toward the Western canon. So we are taking this message to cultural institutions that haven't worked with Wikimedia before. The Khalili Foundation is now reaching out to art museums to encourage them to share images and catalogue data with the Wikimedia projects. We have already uploaded more than 1,100 images of Islamic art and Japanese art as part of the Khalili Collections/Wikimedia UK cultural partnership. As part of the World Festival of Cultural Diversity, the Khalili Foundation is running a series of editathons with partner organisations in the UK.
We have put our lists of artists and masterpieces into a project page where you can see which links are red and which articles have the lowest quality assessments. This is also somewhere to share suggested references. We use Wikidata identifiers, which we hope will make it easy to implement the project page in other languages. The page is situated within WikiProject Visual Arts, but you do not have to be a member of that WikiProject to take part. Improving a linked article, creating a Wikidata item, or even finding a reference that could be used to create an article, are all welcome. We are not just looking to improve the coverage of topics mentioned in our research, but to diversify Wikipedia’s representation of art, so feel free to add artists or topics that you think are lacking.