Learning Content Patterns From Linked Data

Full paper LD4IE 2014 Workshop @ ISWC

Transcript

1. Emir Muñoz
   Fujitsu (Ireland) Limited
   National University of Ireland Galway
   LD4IE 2014 @ ISWC, Riva del Garda, Trentino, Italy. Oct 20th, 2014
   http://bit.ly/1xYTR6Z
   (@emir_munoz)
   

   View Slide

2. View Slide

3. 
   Domain(predicate)  ??
   Range(predicate)  ??
   3
   

   View Slide

4. select distinct ?obj where
   {?sub ?obj}
   Let’s run the following SPARQL query over endpoint…
   And some more ...
   The endpoint response is a table with the values for the isbn property:
   So, what is the correct range for ?
   4
   0
   71090
   6176526
   2
   2.7073
   140043853
   1107020697
   2940013968264
   0978-02-02+02:00
   http://dbpedia.org/resource/N/a
   "?"@en
   "ISBN 0-312-85182-0"@en
   "See text"@en
   "various"@en
   "ISBN 978-0-465-02656-2, ISBN 0-14-017997-6"@en
   "ISBN 0-553-07875-5 & ISBN 0-553-56166-9"@en
   "The Claiming of Sleeping Beauty: ISBN 0-452-26656-4"@en
   "-2.0"^^
   "TBA"@en
   "not available"@en
   "[[#Bibliography"@en
   

   View Slide

5.  LOV Statistics (by July 7th, 2014):
    446 vocabularies
    10 classes and 20 properties in average
   5
   range of isbn is
   http://schema.org/Text
   

   View Slide

6. …but still, is it what I’m looking for? what is the syntax? 6
   

   View Slide

7.  Etymology
    apo- + apsis
    Noun
    apoapsis (plural apoapsides)
    (astronomy) The point of a body's elliptical orbit about
   the system's centre of mass where the distance between the body and
   the centre of mass is at its maximum.
    Property: apoapsis
   [http://en.wiktionary.org/wiki/apoapsis]
   Earth
   Satellite
   dbr:17049_Miron dbo:apoapsis 4.01288e+11
   7
   

   View Slide

8. 8
   https://github.com/dbpedia/extraction-framework/blob/master/
   core/src/main/scala/org/dbpedia/extraction/ontology/OntologyDatatypes.scala
   

   View Slide

9. 
   1488-07-28+02:00 "September 2012"@en "--08-26+02:00"^^
   1982-05-23+02:00 "August 2012"@en "--01-24+02:00"^^
   2007-04-11+02:00 "July 2009"@en "--06-11+02:00"^^
   Lerman et al. (JAIR 2003)
   First column: [NUM-NUM-NUM+NUM:NUM] (plain literal)
   Second column: [ALPHANUM] (plain literal + lang)
   Third column: [--NUM-NUM+NUM:NUM] (typed literal)
   
   9
   

   View Slide

10. Let be the set of
    content patterns.
    Lerman et al. (JAIR 2003)
    More specific categories
    For the input set:
    That generates the following patterns:
    Values are decomposed in tokens, and
    each token is represented by a syntactic
    class.
    10
    

    View Slide

11.  2.4 billion RDF triples
     53,230 properties
    Version 3.9
    Split Method
     19.25% plain literals
     18.02% typed literals
     62.73% without lang or datatype (xsd:string)
    11
    

    View Slide

12.  For apoapsis example, we extracted one pattern
     And we also found some other related properties:
     For date example, we extracted 7 patterns
    http://dbpedia.org/ontology/apoapsis LARGE/FLOAT_NUMBER 1.0
    http://dbpedia.org/ontology/Planet/apoapsis LARGE/FLOAT_NUMBER 1.0
    http://dbpedia.org/ontology/Spacecraft/apoapsis LARGE/FLOAT_NUMBER 1.0
    http://dbpedia.org/property/apoapsis NUMBER 0.9230769230769231
    http://dbpedia.org/property/apoapsis LARGE/FLOAT_NUMBER 0.75213675
    http://dbpedia.org/property/date -- SMALL_NUMBER - SMALL_NUMBER 0.2
    http://dbpedia.org/property/date ALPHANUMERIC MEDIUM_NUMBER 0.166
    http://dbpedia.org/property/date ALPHANUMERIC 2012 0.032
    http://dbpedia.org/property/date ALPHANUMERIC.ALPHANUMERIC 0.012
    And more …
    12
    

    View Slide

13.  The user has this value: “2014-10-20”.
     What property can he use?
     dbp:dateCreated, dbp:dateOfProduction, dbp:dateOpened,
    dbp:dateSigned, dbp:dateOfPremiere, dbp:date, among
    others.
     What is the property dbp:admCtrOf used for?
     "town of republic significance of Meleuz"@en
    (http://dbpedia.org/resource/Meleuz)
     "town of oblast significance of Oktyabrsk"@en
    (http://dbpedia.org/resource/Oktyabrsk)
     "town of republic significance of Sortavala"@en
    (http://dbpedia.org/resource/Sortavala)
      it is used to declare Administrative Control Of
    13
    

    View Slide

14.  Check for atypical values (outliers)
     Close look into the most (in)frequent patterns
     Possible errors during automatic extraction
     For the dbp:isbn property we can find the following
    values:
    "summer or autumn 380"@en "Late November"@en
    "Fall 1040"@en 680
    "December, 67 BC"@en "April-July 1799"@en
    http://dbpedia.org/resource/New_Year's_Day http://dbpedia.org/resource/Second_Interm
    ediate_Period_of_Egypt
    "New moon day of Kartika, celebrations begin two
    days prior and end two days after that date"@en
    Are they or values?
    14
    

    View Slide

15. E-mail: user1@domain.com
    Given name: John
    Surname: Snow
    Birthday: 1986-02-14
    A vCard, may be annotated
    with microformat hCard
    LD4IE Challenge
    2014
    vcard:email mailto : ALPHA PUNCTUATION ALL_LOWERCASE . ALL_LOWERCASE 0.82
    vcard:email mailto : ALPHA PUNCTUATION ALL_LOWERCASE . com 0.69
    vcard:email mailto : ALPHA @ ALPHANUMERIC . ALL_LOWERCASE 0.54
    vcard:email mailto : ALPHA @ ALPHANUMERIC . com 0.46
    vcard:email mailto : ALL_UPPERCASE ****@ ALL_LOWERCASE . ALL_LOWERCASE 0.36
    We can use our database to extract and validate the email:
    vcard:bday NUMBER - SMALL_NUMBER - SMALL_NUMBER 0.5
    vcard:bday MEDIUM_NUMBER - SMALL_NUMBER - SMALL_NUMBER 0.5
    …also the birthday
    15
    

    View Slide

16.  Extraction of lexico-syntactic patterns from LD datasets
     Different use cases:
     Search for properties
     Validation of values
     Information extraction based on patterns
     Future work:
     Study of consistency analysis of knowledge bases
     Extension of patterns to cover other knowledge bases
    Among others
    16
    500,000 content patterns
    

    View Slide

17. http://emunoz.org
    @emir_munoz
    Emir.Munoz@ie.fujistu.com
    https://github.com/emir-munoz/ld-patterns/
    

    View Slide