On 20/09/2019 17:53, Denny Vrandečić wrote: ...
I have been working on a comparison of DBpedia, Wikidata, and Freebase (and since you've read my thesis, you know that's a thing I know a bit about). Simple evaluation, coverage, correctness, nothing dramatically fancy. But I am torn about publishing it, because, d'oh, people may (with good reasons) dismiss it as being biased. And truth be told - the simple fact that I don't know DBpedia as well as I know Wikidata and Freebase might indeed have lead to errors, mistakes, and stuff I missed in the evaluation. But you know what would help?
I would also be very interested in seeing this. I had a closer look at DBpedia recently for a tutorial and was surprised by how different the data is in comparison to Wikidata. A methodological comparison would surely be helpful.
Of course, it has to be fair, taking into account that DBpedia editions are based on a Wikipedia in one language (hence is always missing entities that Wikidata has). For example, I recently computed the difference between the following two:
(1) The set of all pairs of ancestors that one can find by following (paths of) parent relations on EN DBPedia. (2) The set of all pairs of ancestors that one can find by following (paths of) mother/father relations on Wikidata, but visiting only items that are present in English Wikipedia.
I am not sure if this is fair or not, but I found it an interesting setup (non-local effects of incompleteness) -- and (2) is a nice illustration of something you cannot achieve in SPARQL on principled grounds ;-).
Cheers,
Markus