Re: type of http://dbpedia.org/page/Bachelor_of_Arts

Hi Valentina,

I am not sure whether I understand you correctly. There might be cases 
of metonymy in DBpedia, but as far as I can see, Wikipedia is usually 
quite good at separating them via disambiguation pages, I am not sure 
whether there are too many example.

The problem with the degrees, as far as I can tell, is not a metonymy 
one (degrees are just degrees, I have never seen them used to refer to a 
university), but simply a series of shortcomings in DBpedia. What 
happens here inside DBpedia is the following:
* First, we find an infobox which says that someone's almaMater is, say, 
"Princeton University (B.A.)". Both Princeton and B.A. are linked to the 
respective Wikipedia pages.
* The extraction framework extracts two statements from that:
PersonX almaMater Princeton_University, and
PersonX almaMater Bachelor_of_Arts
(the second one being an error, which is very hard to avoid in the 
general case)
* Since that happens a few times, we infer that Bachelor_of_Arts is a 
University.

So in that case, I think it's purely a DBpedia problem. If you are aware 
of any actual cases of metonymy, however, I am curious to hear about that.

All the best,
Heiko



Am 13.10.2014 16:33, schrieb Valentina Presutti:
> Hi Heiko,
>
> thanks for the prompt reply and the explanation.
> However, the interesting thing is that these entities are clearly used 
> with more than one sense (at least in the US culture), so the issue 
> comes from this fact originally in my opinion.
> I mentioned two cases here, but if you check you can see that all 
> these types of entities (Degrees) have the same problem.
>
> My suggestion (if that can help) is to identify such metonym cases and 
> have a special approach: having different entities as the number of 
> senses.
>
> However, the Wikipedia page of such entities defines them as 
> degrees…not sure if this can be useful to notice for you.
>
> Valentina
>
> On 13 Oct 2014, at 09:03, Heiko Paulheim 
> <heiko@informatik.uni-mannheim.de 
> <mailto:heiko@informatik.uni-mannheim.de>> wrote:
>
>> Hi Valentina,
>>
>> (and CCing the DBpedia discussion list)
>>
>> this is an effect of the heuristic typing we employ in DBpedia [1]. 
>> It works correctly in many cases, and sometimes it fails - as for 
>> these examples (the classic tradeoff between coverage and precision).
>>
>> To briefly explain how the error comes into existence: we look at the 
>> distribution of types that occur for the ingoing properties of an 
>> untyped instance. For dbpedia:Bachelor_of_Arts, there are, among 
>> others, 208 ingoing properties with the predicate 
>> dbpedia-owl:almaMater (which is already questionable). For that 
>> predicate, 87.6% of the objects are of type dbpedia-owl:University. 
>> So we have a strong pattern, with many supporting statements, and we 
>> conclude that dbpedia:Bachelor_of_Arts is a university. That 
>> mechanism, as I said, works reasonable well, but sometimes fails at 
>> single instances, like this one. For dbpedia:Academic_degree, you'll 
>> find similar questionable statements involving that instace, that 
>> mislead the heuristic typing algorithm.
>>
>> With the 2014 release, we further tried to reduce errors like these 
>> by filtering common nouns using WordNet before assigning types to 
>> instances, but both "Academic degree" and "Bachelor of Arts" escaped 
>> our nets here :-(
>>
>> The public DBpedia endpoint loads both the infobox based types and 
>> the heuristic types. If you need a "clean" version, I advise you to 
>> set up a local endpoint and load only the infobox based types into it.
>>
>> Best,
>> Heiko
>>
>> [1]http://www.heikopaulheim.com/documents/iswc2013.pdf
>>
>>
>>
>>
>> Am 13.10.2014 02:42, schrieb Valentina Presutti:
>>> Dear all,
>>>
>>> I noticed that dbpedia:Bachelor_of_Arts 
>>> <http://dbpedia.org/page/Bachelor_of_Arts>, as well as other similar 
>>> entities (dbpedia:Bachelor_of_Engineering, 
>>> dbpedia:Bachelor_of_Science, etc.), is typed as dbpedia-owl:University
>>> I would expect a type like “Academic Degree” but if you look at
>>> dbpedia:Academic_Degree, its type is again dbpedia-owl:University
>>>
>>> however, its definition is (according to dbpedia):
>>>
>>> "An academic degree is a college or university diploma, often 
>>> associated with a title and sometimes associated with an academic 
>>> position, which is usually awarded in recognition of the recipient 
>>> having either satisfactorily completed a prescribed course of study 
>>> or having conducted a scholarly endeavour deemed worthy of his or 
>>> her admission to the degree. The most common degrees awarded today 
>>> are associate, bachelor's, master's, and doctoral degrees.”
>>>
>>> Showing that there are at least two different meanings associated 
>>> with the term: college/university and title.
>>> I thing that different meanings should be separated so as to allow 
>>> applications to refer to the different entities: a university or a 
>>> title.
>>>
>>> At least for me this causes errors in automatic relation extraction...
>>>
>>> Wdyt?
>>>
>>> Valentina
>>
>> -- 
>> Prof. Dr. Heiko Paulheim
>> Data and Web Science Group
>> University of Mannheim
>> Phone: +49 621 181 2646
>> B6, 26, Room C1.08
>> D-68159 Mannheim
>>
>> Mail:heiko@informatik.uni-mannheim.de
>> Web:www.heikopaulheim.com
>

-- 
Prof. Dr. Heiko Paulheim
Data and Web Science Group
University of Mannheim
Phone: +49 621 181 2646
B6, 26, Room C1.08
D-68159 Mannheim

Mail: heiko@informatik.uni-mannheim.de
Web: www.heikopaulheim.com