On Sun, Feb 21, 2016 at 4:25 PM, Markus Krötzsch
<markus(a)semantic-mediawiki.org <mailto:markus@semantic-mediawiki.org>>
wrote:
On 21.02.2016 20 <tel:21.02.2016%2020>:37, Tom Morris wrote:
On Sun, Feb 21, 2016 at 11:41 AM, Markus Krötzsch
<markus(a)semantic-mediawiki.org
<mailto:markus@semantic-mediawiki.org>
<mailto:markus@semantic-mediawiki.org
<mailto:markus@semantic-mediawiki.org>>>
wrote:
On 18.02.2016 15:59, Lydia Pintscher wrote:
Thomas, Denny, Sebastian, Thomas, and I have published
a paper
which was
accepted for the industry track at WWW 2016. It covers
the migration
from Freebase to Wikidata. You can now read it here:
http://research.google.com/pubs/archive/44818.pdf
Is it possible that you have actually used the flawed
statistics
from the Wikidata main page regarding the size of the
project? 14.5M
items in Aug 2015 seems far too low a number. Our RDF
exports from
mid August already contained more than 18.4M items. It
would be nice
to get this fixed at some point. There are currently almost 20M
items, and the main page still shows only 16.5M.
Numbers are off throughout the paper. They also quote 48M
instead of
58M topics for Freebase and mischaracterize some other key
points. They
key number is that 3.2 billion facts for 58 million topics has
generated
106,220 new statements for Wikidata. If my calculator had more
decimal
places, I could tell you what percentage that is.
Obviously, any tool can only import statements for which we have
items and properties at all, so the number of importable facts is
much lower.
Obviously, but "much lower" from 3.2B is probably something like
50M-300M, not 0.1M.
That estimate might be a bit off. The paper contains a detailed
discussion of this aspect. The total number of statements that could be
translated from Freebase to Wikidata is given as 17M, of which only 14M
were new. So this seems to be the current upper bound of what you could
import with PS or any other tool. The authors mention that this already
includes more than 90% of the "reviewed" content of Freebase that refers
to Wikidata items. The paper seems to suggest that these mapped+reviewed
statements were already imported directly -- maybe Lydia could clarify
if this was the case.
It seems that if you want to go to the dimensions that you refer to
(50M/300M/3200M) you would need to map more Wikidata items to Freebase
topics in some way. The paper gives several techniques that were used to
obtain mappings that are already more than what we have stored in
Wikidata now. So it is probably not the lack of mappings but the lack of
items that is the limit here. Data can only be imported if we have a
page at all ;-)
Btw. where do the 100K imported statements come from that you mentioned
here? I was also interested in that number but I could not find it in
the paper.
Markus