a paper and a great presentation. The bottom line is that when you know what to suggest to people; when you make it personal, the result is what you would hope. Consider, 3.2 times the number of articles created and two times more articles created than without personalised recommendations.
There is math involved, obviously, but the gist is that when suggestions are in line with previous activities, people will be triggered to do more. When you listen to the presentation, this first experiment asks people to translate from English. The assumption is that English covers more than most.
The slides of the presentation include visualisations showing the coverage of several Wikipedias. When you consider them, it becomes clear where the Wikimedia projects are challenged.
Leila Zia, the presenter makes it clear; all this would not be possible without Wikidata. One thing where Wikidata is different from the assumptions of the research is that there is an increasing number of subjects that have no links to Wiki(m/p)edia articles at all. Many of these are connected to existing content as they share common statements, statements like "profession: soccer player" of "award received: whatever award".
When totally new subjects are to be considered, there is already plenty that might be suggested in Wikidata itself.