1. Semantic Web
Technologies
Lecture 6: Applications in the Web of Data
06: Named Entity Recognition
Dr. Harald Sack
Hasso Plattner Institute for IT Systems Engineering
University of Potsdam
Spring 2013
This file is licensed under the Creative Commons Attribution-NonCommercial 3.0 (CC BY-NC 3.0)

2. 2
Lecture 6: Applications in the Web of Data
Open HPI - Course: Semantic Web Technologies
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

3. 3
06 - Named Entity Recognition
Open HPI - Course: Semantic Web Technologies - Lecture 6: Applications in the Web of Data
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam

4. 4
Meaning
sender
Experience
receiver
Context
Concept
symbolizes refers to
Experience
Symbol Object
stands for
„Jaguar“
Pragmatics Ogden, Richards: The Meaning of Meaning:
Semantic Web Technologies , Dr. Harald Sack, Hasso Plattner Institute, University of Study of the Influence of Language upon Thought and of the Science of Symbolism (1923)
A Potsdam

5. Armstrong

7. ,Armstrong‘ is more than just a character string

8. ,Armstrong‘ is more than just a character string
Neil Armstrong

9. ,Armstrong‘ is more than just a character string
Neil Armstrong
is a
Astronaut

10. ,Armstrong‘ is more than just a character string
Neil Armstrong
is a
Astronaut
subClassOf
Science Occupation

11. ,Armstrong‘ is more than just a character string
Neil Armstrong
is a
Astronaut
subClassOf
Science Occupation
subClassOf
Employment

12. ,Armstrong‘ is more than just a character string
Neil Armstrong
is a is a
Astronaut Person
subClassOf
Science Occupation
subClassOf
Employment

13. ,Armstrong‘ is more than just a character string
Neil Armstrong
is a is a
Astronaut Person
subClassOf
Science Occupation
subClassOf
has an
Employment

14. ,Armstrong‘ is more than just a character string
Neil Armstrong Entities
is a is a
Ontologies
Astronaut Person
subClassOf
Science Occupation
subClassOf
has an
Employment

15. ,Armstrong‘ is more than just a character string
Neil Armstrong Entities
is a is a
Ontologies
Astronaut Person
subClassOf
is NOT a
Science Occupation
subClassOf
has an
Employment

16. ,Armstrong‘ is more than just a character string
Neil Armstrong Entities
is a is a
Ontologies
same as
Cosmonaut Astronaut Person
subClassOf
is NOT a
Science Occupation
subClassOf
has an
Employment

17. ,Armstrong‘ is more than just a character string
Juri Gagarin
is a Neil Armstrong Entities
is a is a
Ontologies
same as
Cosmonaut Astronaut Person
subClassOf
is NOT a
Science Occupation
subClassOf
has an
Employment

18. ,Armstrong‘ is more than just a character string
Juri Gagarin
is a Neil Armstrong
Name d Entity Recognition Entities
(also Entity Identificati on or Entity Extraction)
tomic elements...inis a
is a to
„lo cating and classifying a sOntologies
sames names, person ,
predefined categories such a as
Kosmonaut Astronautf time,
so Person
organizatio ns, locations, expression
quantities, m oneta , etc.“
ry valuessubClassOf is NOT a
Science Occupation
79)
C.J.Rijsbe rgen, Information Retrieval (19
subClassOf
has an
Employment

19. Where does the knowledge come from...?

20. Where does the knowledge come from...?

21. Where does the knowledge come from...?

22. Web of Data = Linked Open Data

23. Armstrong

24. Armstrong
Entity Mapping
Neil Armstrong
is a is a
Astronaut Person
subClassOf
Science Occupation
subClassOf
Employment

25. 12
Meaning
sender
Experience
receiver
Concept
symbolizes refers to
Experience
http://commons.wikimedia.org/wiki/User:McSmit
Symbol Object
stands for
Armstrong
Pragmatics Ogden, Richards: The Meaning of Meaning:
Semantic Web Technologies , Dr. Harald Sack, Hasso Plattner Institute, University of Study of the Influence of Language upon Thought and of the Science of Symbolism (1923)
A Potsdam

26. 12
Meaning
sender
Experience
receiver
Context
Concept
symbolizes refers to
Experience
http://commons.wikimedia.org/wiki/User:McSmit
Symbol Object
stands for
Armstrong
Pragmatics Ogden, Richards: The Meaning of Meaning:
Semantic Web Technologies , Dr. Harald Sack, Hasso Plattner Institute, University of Study of the Influence of Language upon Thought and of the Science of Symbolism (1923)
A Potsdam

27. Armstrong landed the Eagle on the Moon.

28. Armstrong landed the Eagle on the Moon.
Determine all possible Entity Mapping Candidates
• linguistic analysis (POS tagging)
• normalization
• encoding and spelling
• special (language dependent) characters
• language dependent spellings
• abbreviations, acronyms
• type dependent spellings
• alternative names and synonyms
• fuzzy string mapping
• ...

29. Armstrong landed the Eagle on the Moon.
Determine all possible Entity Mapping Candidates

30. Armstrong landed the Eagle on the Moon.
Determine all possible Entity Mapping Candidates
Anton Armstrong
Armstrong, Ontario
Armstrong Tools Ian Armstrong
Armstrong, Ontario
Armstrong (car) Edward Armstrong
Armstrong, Florida
Neil Armstrong
Armstrong (moon crater)
Armstrong County, Texas Gary Armstrong
The Armstrongs George Armstrong
Armstrong Tunnel
Armstrong Bridge
Louis Armstrong Craig Armstrong
The Armstrong Twins
Lance Armstrong
+ 400 more...

31. Armstrong landed the Eagle on the Moon.
Entity Selection process is determined by
• context
• ambiguity of source data / mapping
• accuracy /reliability of source data / mapping

32. Armstrong landed the Eagle on the Moon.
Entity Selection process is determined by
• context
• ambiguity of source data / mapping
• accuracy /reliability of source data / mapping
Anton Armstrong
Armstrong, Ontario
Armstrong Tools Ian Armstrong
Armstrong, Ontario
Armstrong (car) Edward Armstrong
Armstrong, Florida
Neil Armstrong
Armstrong (moon crater)
Armstrong County, Texas Gary Armstrong
The Armstrongs George Armstrong
Armstrong Tunnel
Armstrong Bridge
Louis Armstrong Craig Armstrong
The Armstrong Twins
Lance Armstrong
+ 400 more...

33. Armstrong landed the Eagle on the Moon.
Consider all entities within the same context
Armstrong Eagle Moon
448 entities 95 entities 156 entities
Man on the Moon (film)
George Armstrong Custer Eagle (Bird) Moon (song)
Neil Armstrong Eagle (heraldry) Moon Son-Ri
The Armstrong Twins USCGC Eagle Moon 44
C Moon
Armstrong, Florida The Eagle (2011 film)
Eagle (comic) The Moon (Tarot card)
Craig Armstrong
Armstrong, Ontario Man on the Moon (soundtrack)
Eagle (song) Moon
Armstrong (Moon Crater) Eagle (lunar module)
Armstrong Gun The Eagle (newspaper) Man on the Moon (musical)
Armstrong‘s Theorem War Eagle Mr. Moon (song)
Eagle (Moon Crater)
Louis Armstrong International Airport Moon (Band)
The Eagle (Pub)
Armstrong County, Texass Moon OS
Eagle TV Eagle Falls (Washington) Moon 83
Joe Armstrong Lottie Moon
Ian Armstrong Eagle (racehorse) Edgar Moon
Armstrong Tunnel Armstrong Tunnel
Armstrong Automobile John H. Eagle Darvin Moon
Sir Thomas Armstrong Eagle (typeface) Gary Moon William Moon
Louis Armstrong Angela Eagle Francis Moon
Armstrong (British Columbia) Linda Eagle Robert Charles Moon
Karen Armstrong
Allan Moon
Curtis Armstrong James Philipp Eagle Fly me to the Moon (song)
Hilary Armstrong Black Moon
Ban-Ki Moon
Gillian Armstrong
William L. Armstrong

34. Named Entity Recognition Strategies
Entity Selection Process
Select matching entities from all possible candidate entities:
• Popularity based strategies • reference text corpus
(wikipedia)
• Linguistical strategies
• link graph (wikipedia)
• Statistical strategies
• semantic graph
• Semantic based strategies (dbpedia)
General Approach
1. Make an assumption
2. Do the strategies support or contradict your assumption
3. Make decision according to logical and probabilistic rules/constraints
N. Ludwig, H. Sack, “Named entity recognition for user-generated tags,TIR 2011

35. Armstrong landed the Eagle on the Moon.
Consider all entities within the same context

36. Armstrong landed the Eagle on the Moon.
Consider all entities within the same context

37. Armstrong landed the Eagle on the Moon.
Consider all entities within the same context

38. Armstrong landed the Eagle on the Moon.
Consider all entities within the same context

39. Armstrong landed the Eagle on the Moon.
Consider all entities within the same context

40. Armstrong landed the Eagle on the Moon.
Consider all entities within the same context

41. Armstrong landed the Eagle on the Moon.
Entity Selection Process
(Semantic) Graph Analysis
Armstrong Eagle Moon
448 entities 95 entities 156 entities
Man on the Moon (film)
George Armstrong Custer Eagle (Bird) Moon (song)
Neil Armstrong Eagle (heraldry) Moon Son-Ri
The Armstrong Twins USCGC Eagle Moon 44
C Moon
Armstrong, Florida The Eagle (2011 film)
Eagle (comic) The Moon (Tarot card)
Craig Armstrong
Armstrong, Ontario Moon Man on the Moon (soundtrack)
Eagle (song)
Armstrong (Moon Crater) Eagle (lunar module)
Armstrong Gun The Eagle (newspaper) Man on the Moon (musical)
Armstrong‘s Theorem War Eagle Mr. Moon (song)
Eagle (Moon Crater)
Louis Armstrong International Airport Moon (Band)
The Eagle (Pub)
Armstrong County, Texass Moon OS
Eagle TV Eagle Falls (Washington) Moon 83
Joe Armstrong Lottie Moon
Ian Armstrong Eagle (racehorse) Edgar Moon
Armstrong Tunnel Armstrong Tunnel
Armstrong Automobile John H. Eagle Darvin Moon
Sir Thomas Armstrong Eagle (typeface) Gary Moon William Moon
Louis Armstrong Angela Eagle Francis Moon
Armstrong (British Columbia) Linda Eagle Robert Charles Moon
Karen Armstrong
Allan Moon
Curtis Armstrong James Philipp Eagle Fly me to the Moon (song)
Hilary Armstrong Black Moon
Ban-Ki Moon
Gillian Armstrong
William L. Armstrong
N. Steinmetz, H.Sack: Semantic Multimedia Information Retrieval Based on Contextual Descriptions, 2013

42. Armstrong landed the Eagle on the Moon.
http://dbpedia.org/resource/Neil_Armstrong
http://dbpedia.org/resource/Apollo_Lunar_Module
http://dbpedia.org/resource/Moon

43. 22
07 - Semantic Search
Open HPI - Course: Semantic Web Technologies - Lecture 6: Applications in the Web of Data
Semantic Web Technologies , Dr. Harald Sack, Hasso-Plattner-Institut, Universität Potsdam