Cross-language Explicit Semantic Analysis (CL-ESA)

Plagiate, und wie (gut) man sie erkennen kann
Technologien zur Wiederverwendung von Texten aus dem Web
Martin Potthast
Bauhaus-Universität Weimar
www.webis.de
Wie Menschen plagiieren
Suche
Copy‘n‘Paste
Modifikation
Diss ;-)
Search
2
I‘m Feeling Lucky
c www.webis.de 2011
Wie Maschinen Plagiate erkennen
q
Wie können sprachübergreifende Plagiate erkannt werden?
q
Wie verlässlich sind Algorithmen zur Plagiatserkennung?
Dokumentkollektion
Verdächtiges
Dokument
Kandidatenretrieval
Kandidatendokumente
Erkennung von Plagiaten
Detaillierter
Vergleich
Wissensbasierte
Nachverarbeitung
Verdächtige
Passagen
3
c www.webis.de 2011
Wie Maschinen Plagiate erkennen
q
Wie können sprachübergreifende Plagiate erkannt werden?
q
Wie verlässlich sind Algorithmen zur Plagiatserkennung?
Dokumentkollektion
Verdächtiges
Dokument
Kandidatenretrieval
Kandidatendokumente
Erkennung von Plagiaten
Detaillierter
Vergleich
Wissensbasierte
Nachverarbeitung
Verdächtige
Passagen
4
c www.webis.de 2011
Messung sprachübergreifender Textähnlichkeit
Alan Turing was conceived at Chatrapur, Orissa, India. His father was
a member of the Indian Civil Service. He and his wife wanted Alan
to be brought up in England, so
they returned to Maida Vale,
London, where Alan Turing was
born on 23 June 1912. He had an
elder brother, John. His father's
civil service commission was still
active, and during Turing's childhood years his parents travelled
between Hastings, England and
India, leaving their two sons to stay
with a retired Army couple. Very
early in life, Turing showed signs of
the genius he was to later prominently display.
5
Alan Mathison Turing was born on
23 June 1912. His father was Julius
Mathison Turing, member of the
civil service in India, and his
mother Ethel Sara Turing, the
daughter of Edward Waller Stoney.
Alan's childhood was spent with his
elder brother John, living with a
retired Army couple near Hastings,
England. His parents returned to
India until the end of his father‘s
civil service commission, and visited when they could. Signs of
Turing‘s genius showed early in his
life. It is reported that he taught
himself reading in less than three
weeks.
c www.webis.de 2011
Messung sprachübergreifender Textähnlichkeit
Alan Turing was conceived at Chatrapur, Orissa, India. His father was
a member of the Indian Civil Service. He and his wife wanted Alan
to be brought up in England, so
they returned to Maida Vale,
London, where Alan Turing was
born on 23 June 1912. He had an
elder brother, John. His father's
civil service commission was still
active, and during Turing's childhood years his parents travelled
between Hastings, England and
India, leaving their two sons to stay
with a retired Army couple. Very
early in life, Turing showed signs of
the genius he was to later prominently display.
6
Alan Mathison Turing was born on
23 June 1912. His father was Julius
Mathison Turing, member of the
civil service in India, and his
mother Ethel Sara Turing, the
daughter of Edward Waller Stoney.
Alan's childhood was spent with his
elder brother John, living with a
retired Army couple near Hastings,
England. His parents returned to
India until the end of his father‘s
civil service commission, and visited when they could. Signs of
Turing‘s genius showed early in his
life. It is reported that he taught
himself reading in less than three
weeks.
c www.webis.de 2011
Messung sprachübergreifender Textähnlichkeit
Alan Mathison Turing was born on
23 June 1912. His father was Julius
Mathison Turing, member of the
civil service in India, and his
mother Ethel Sara
5Turing, the
daughter of Edward Waller Stoney.
Alan's childhood 0
was spent with his
elder brother John,
living with a
1
retired Army couple near Hastings,
England. His parents returned to
India until the end of his father‘s
1
civil service commission, and visited when they could.
2 Signs of
Turing‘s genius showed early in his
life. It is reported0
that he taught
himself reading in less than three
weeks.
...
7
...
...
Alan Turing was conceived at Chatrapur, Orissa, India. His father was
a member of the Indian Civil Service. He and his wife wanted Alan
to
be brought up in4
England, so
turing
they returned to Maida Vale,
travel where Alan1Turing was
London,
born
on 23 June 1912.
He had an
teach
0
elder brother, John. His father's
civil service commission was still
active, and during Turing's childarmy
1
hood years his parents travelled
between
alan Hastings,3England and
India, leaving their two sons to stay
active
with
a retired Army1
couple. Very
early in life, Turing showed signs of
the genius he was to later prominently display.
c www.webis.de 2011
Messung sprachübergreifender Textähnlichkeit
ϕ
Alan Mathison Turing was born on
23 June 1912. His father was Julius
Mathison Turing, member of the
civil service in India, and his
mother Ethel Sara
5Turing, the
daughter of Edward Waller Stoney.
Alan's childhood 0
was spent with his
elder brother John,
living with a
1
retired Army couple near Hastings,
England. His parents returned to
India until the end of his father‘s
1
civil service commission, and visited when they could.
2 Signs of
Turing‘s genius showed early in his
life. It is reported0
that he taught
himself reading in less than three
weeks.
- Euklidische Distanz
- Skalarprodukt
- Kosinusähnlichkeit
...
8
...
...
Alan Turing was conceived at Chatrapur, Orissa, India. His father was
a member of the Indian Civil Service. He and his wife wanted Alan
to
be brought up in4
England, so
turing
they returned to Maida Vale,
travel where Alan1Turing was
London,
born
on 23 June 1912.
He had an
teach
0
elder brother, John. His father's
civil service commission was still
active, and during Turing's childarmy
1
hood years his parents travelled
between
alan Hastings,3England and
India, leaving their two sons to stay
active
with
a retired Army1
couple. Very
early in life, Turing showed signs of
the genius he was to later prominently display.
c www.webis.de 2011
Messung sprachübergreifender Textähnlichkeit
Alan Turing was conceived at Chatrapur, Orissa, India. His father was
a member of the Indian Civil Service. He and his wife wanted Alan
to be brought up in England, so
they returned to Maida Vale,
London, where Alan Turing was
born on 23 June 1912. He had an
elder brother, John. His father's
civil service commission was still
active, and during Turing's childhood years his parents travelled
between Hastings, England and
India, leaving their two sons to stay
with a retired Army couple. Very
early in life, Turing showed signs of
the genius he was to later prominently display.
9
Turings Vater Julius Mathison
Turing, ein britischer Staatsdiener
in Chatrapur, Indien, und dessen
Frau Ethel Sara wollten, dass ihr
Kind in Großbritannien geboren
wird. Deshalb kehrten sie nach
London-Paddington zurück, wo
Alan Turing am 23. Juni 1912 zur
Welt kam. Da der Staatsdienst
seines Vaters noch nicht beendet
war, pendelte dieser während
Turings Kindheit zwischen England
und Indien. Seine Familie ließ er
aus Furcht vor Gefahren in der
britischen Kolonie bei Freunden in
England zurück. Schon in frühester
Kindheit zeigte sich die hohe Begabung und Intelligenz Turings.
c www.webis.de 2011
Messung sprachübergreifender Textähnlichkeit
Alan Turing was conceived at Chatrapur, Orissa, India. His father was
a member of the Indian Civil Service. He and his wife wanted Alan
to be brought up in England, so
they returned to Maida Vale,
London, where Alan Turing was
born on 23 June 1912. He had an
elder brother, John. His father's
civil service commission was still
active, and during Turing's childhood years his parents travelled
between Hastings, England and
India, leaving their two sons to stay
with a retired Army couple. Very
early in life, Turing showed signs of
the genius he was to later prominently display.
10
Turings Vater Julius Mathison
Turing, ein britischer Staatsdiener
in Chatrapur, Indien, und dessen
Frau Ethel Sara wollten, dass ihr
Kind in Großbritannien geboren
wird. Deshalb kehrten sie nach
London-Paddington zurück, wo
Alan Turing am 23. Juni 1912 zur
Welt kam. Da der Staatsdienst
seines Vaters noch nicht beendet
war, pendelte dieser während
Turings Kindheit zwischen England
und Indien. Seine Familie ließ er
aus Furcht vor Gefahren in der
britischen Kolonie bei Freunden in
England zurück. Schon in frühester
Kindheit zeigte sich die hohe Begabung und Intelligenz Turings.
c www.webis.de 2011
Messung sprachübergreifender Textähnlichkeit
Turings Vater Julius Mathison
Turing, ein britischer Staatsdiener
in Chatrapur, Indien, und dessen
Frau Ethel Sara wollten, dass ihr
Kind in Großbritannien
5 geboren
wird. Deshalb kehrten sie nach
0 zurück, wo
London-Paddington
Alan Turing am 23.
Juni 1912 zur
0
Welt kam. Da der Staatsdienst
seines Vaters noch nicht beendet
war, pendelte dieser während
2
Turings Kindheit zwischen England
und Indien. Seine1Familie ließ er
aus Furcht vor Gefahren in der
1bei Freunden in
britischen Kolonie
England zurück. Schon in frühester
Kindheit zeigte sich die hohe Begabung und Intelligenz Turings.
...
11
...
...
Alan Turing was conceived at Chatrapur, Orissa, India. His father was
a member of the Indian Civil Service. He and his wife wanted Alan
to
be brought up in4
England, so
turing
they returned to Maida Vale,
travel where Alan1Turing was
London,
born
He had an
twoon 23 June 1912.
1
elder brother, John. His father's
civil service commission was still
active, and during Turing's childbritisch
0
hood years his parents travelled
between
Hastings, 0
England and
beendet
India, leaving their two sons to stay
alan
with
a retired Army3
couple. Very
early in life, Turing showed signs of
the genius he was to later prominently display.
c www.webis.de 2011
Messung sprachübergreifender Textähnlichkeit
ϕ
Turings Vater Julius Mathison
Turing, ein britischer Staatsdiener
in Chatrapur, Indien, und dessen
Frau Ethel Sara wollten, dass ihr
Kind in Großbritannien
5 geboren
wird. Deshalb kehrten sie nach
0 zurück, wo
London-Paddington
Alan Turing am 23.
Juni 1912 zur
0
Welt kam. Da der Staatsdienst
seines Vaters noch nicht beendet
war, pendelte dieser während
2
Turings Kindheit zwischen England
und Indien. Seine1Familie ließ er
aus Furcht vor Gefahren in der
1bei Freunden in
britischen Kolonie
England zurück. Schon in frühester
Kindheit zeigte sich die hohe Begabung und Intelligenz Turings.
ausgenommen
- Syntaxüberlappung
- Autom. Übersetzung
...
12
...
...
Alan Turing was conceived at Chatrapur, Orissa, India. His father was
a member of the Indian Civil Service. He and his wife wanted Alan
to
be brought up in4
England, so
turing
they returned to Maida Vale,
travel where Alan1Turing was
London,
born
He had an
twoon 23 June 1912.
1
elder brother, John. His father's
civil service commission was still
active, and during Turing's childbritisch
0
hood years his parents travelled
between
Hastings, 0
England and
beendet
India, leaving their two sons to stay
alan
with
a retired Army3
couple. Very
early in life, Turing showed signs of
the genius he was to later prominently display.
c www.webis.de 2011
Cross-language Explicit Semantic Analysis (CL-ESA)
4
...
1
13
ϕ
Turings Vater Julius Mathison
Turing, ein britischer Staatsdiener
in Chatrapur, Indien, und dessen
Frau Ethel wollten, dass ihr Kind in
Großbritannien geboren wird.
Deshalb kehrten sie nach
London-Paddington zurück, wo
Alan Turing am 23. Juni 1912 zur
Welt kam. Da der Staatsdienst
seines Vaters noch nicht beendet
war, pendelte dieser während
Turings Kindheit zwischen England
und Indien. Seine Familie ließ er
aus Furcht vor Gefahren in der
britischen Kolonie bei Freunden in
England zurück. Schon in frühester
Kindheit zeigte sich die hohe
Begabung und Intelligenz Turings.
5
...
Alan Turing was conceived at
Chatrapur, Orissa, India. His father
was a member of the Indian Civil
Service. He and his wife wanted
Alan to be brought up in England,
so they returned to Maida Vale,
London, where Alan Turing was
born on 23 June 1912. He had an
elder brother, John. His father's
civil service commission was still
active, and during Turing's
childhood years his parents
travelled between Hastings,
England and India, leaving their
two sons to stay with a retired
Army couple. Very early in life,
Turing showed signs of the genius
he was to later prominently display.
0
c www.webis.de 2011
Cross-language Explicit Semantic Analysis (CL-ESA)
4
...
1
...
14
ϕ
Turings Vater Julius Mathison
Turing, ein britischer Staatsdiener
in Chatrapur, Indien, und dessen
Frau Ethel wollten, dass ihr Kind in
Großbritannien geboren wird.
Deshalb kehrten sie nach
London-Paddington zurück, wo
Alan Turing am 23. Juni 1912 zur
Welt kam. Da der Staatsdienst
seines Vaters noch nicht beendet
war, pendelte dieser während
Turings Kindheit zwischen England
und Indien. Seine Familie ließ er
aus Furcht vor Gefahren in der
britischen Kolonie bei Freunden in
England zurück. Schon in frühester
Kindheit zeigte sich die hohe
Begabung und Intelligenz Turings.
5
...
Alan Turing was conceived at
Chatrapur, Orissa, India. His father
was a member of the Indian Civil
Service. He and his wife wanted
Alan to be brought up in England,
so they returned to Maida Vale,
London, where Alan Turing was
born on 23 June 1912. He had an
elder brother, John. His father's
civil service commission was still
active, and during Turing's
childhood years his parents
travelled between Hastings,
England and India, leaving their
two sons to stay with a retired
Army couple. Very early in life,
Turing showed signs of the genius
he was to later prominently display.
0
...
c www.webis.de 2011
Cross-language Explicit Semantic Analysis (CL-ESA)
4
...
1
...
15
ϕ
Turings Vater Julius Mathison
Turing, ein britischer Staatsdiener
in Chatrapur, Indien, und dessen
Frau Ethel wollten, dass ihr Kind in
Großbritannien geboren wird.
Deshalb kehrten sie nach
London-Paddington zurück, wo
Alan Turing am 23. Juni 1912 zur
Welt kam. Da der Staatsdienst
seines Vaters noch nicht beendet
war, pendelte dieser während
Turings Kindheit zwischen England
und Indien. Seine Familie ließ er
aus Furcht vor Gefahren in der
britischen Kolonie bei Freunden in
England zurück. Schon in frühester
Kindheit zeigte sich die hohe
Begabung und Intelligenz Turings.
5
...
Alan Turing was conceived at
Chatrapur, Orissa, India. His father
was a member of the Indian Civil
Service. He and his wife wanted
Alan to be brought up in England,
so they returned to Maida Vale,
London, where Alan Turing was
born on 23 June 1912. He had an
elder brother, John. His father's
civil service commission was still
active, and during Turing's
childhood years his parents
travelled between Hastings,
England and India, leaving their
two sons to stay with a retired
Army couple. Very early in life,
Turing showed signs of the genius
he was to later prominently display.
0
...
c www.webis.de 2011
Cross-language Explicit Semantic Analysis (CL-ESA)
4
...
1
...
16
ϕ
Turings Vater Julius Mathison
Turing, ein britischer Staatsdiener
in Chatrapur, Indien, und dessen
Frau Ethel wollten, dass ihr Kind in
Großbritannien geboren wird.
Deshalb kehrten sie nach
London-Paddington zurück, wo
Alan Turing am 23. Juni 1912 zur
Welt kam. Da der Staatsdienst
seines Vaters noch nicht beendet
war, pendelte dieser während
Turings Kindheit zwischen England
und Indien. Seine Familie ließ er
aus Furcht vor Gefahren in der
britischen Kolonie bei Freunden in
England zurück. Schon in frühester
Kindheit zeigte sich die hohe
Begabung und Intelligenz Turings.
5
...
Alan Turing was conceived at
Chatrapur, Orissa, India. His father
was a member of the Indian Civil
Service. He and his wife wanted
Alan to be brought up in England,
so they returned to Maida Vale,
London, where Alan Turing was
born on 23 June 1912. He had an
elder brother, John. His father's
civil service commission was still
active, and during Turing's
childhood years his parents
travelled between Hastings,
England and India, leaving their
two sons to stay with a retired
Army couple. Very early in life,
Turing showed signs of the genius
he was to later prominently display.
0
...
c www.webis.de 2011
Cross-language Explicit Semantic Analysis (CL-ESA)
Alan Turing was conceived at
Chatrapur, Orissa, India. His father
was a member of the Indian Civil
Service. He and his wife wanted
Alan to be brought up in England,
so they returned to Maida Vale,
London, where Alan Turing was
born on 23 June 1912. He had an
elder brother, John. His father's
civil service commission was still
active, and during Turing's
childhood years his parents
travelled between Hastings,
England and India, leaving their
two sons to stay with a retired
Army couple. Very early in life,
Turing showed signs of the genius
he was to later prominently display.
4
Turings Vater Julius Mathison
Turing, ein britischer Staatsdiener
in Chatrapur, Indien, und dessen
Frau Ethel wollten, dass ihr Kind in
Großbritannien geboren wird.
Deshalb kehrten sie nach
London-Paddington zurück, wo
Alan Turing am 23. Juni 1912 zur
Welt kam. Da der Staatsdienst
seines Vaters noch nicht beendet
war, pendelte dieser während
Turings Kindheit zwischen England
und Indien. Seine Familie ließ er
aus Furcht vor Gefahren in der
britischen Kolonie bei Freunden in
England zurück. Schon in frühester
Kindheit zeigte sich die hohe
Begabung und Intelligenz Turings.
5
...
...
ϕ
1
0
5
2
3
...
1
...
...
17
...
...
...
2
2
6
2
c www.webis.de 2011
Cross-language Explicit Semantic Analysis (CL-ESA)
Alan Turing was conceived at
Chatrapur, Orissa, India. His father
was a member of the Indian Civil
Service. He and his wife wanted
Alan to be brought up in England,
so they returned to Maida Vale,
London, where Alan Turing was
born on 23 June 1912. He had an
elder brother, John. His father's
civil service commission was still
active, and during Turing's
childhood years his parents
travelled between Hastings,
England and India, leaving their
two sons to stay with a retired
Army couple. Very early in life,
Turing showed signs of the genius
he was to later prominently display.
4
Turings Vater Julius Mathison
Turing, ein britischer Staatsdiener
in Chatrapur, Indien, und dessen
Frau Ethel wollten, dass ihr Kind in
Großbritannien geboren wird.
Deshalb kehrten sie nach
London-Paddington zurück, wo
Alan Turing am 23. Juni 1912 zur
Welt kam. Da der Staatsdienst
seines Vaters noch nicht beendet
war, pendelte dieser während
Turings Kindheit zwischen England
und Indien. Seine Familie ließ er
aus Furcht vor Gefahren in der
britischen Kolonie bei Freunden in
England zurück. Schon in frühester
Kindheit zeigte sich die hohe
Begabung und Intelligenz Turings.
5
...
...
ϕ
1
0
ϕ
ϕ
5
...
3
...
1
...
6
2
0.2
...
...
18
2
...
0.1
...
...
2
2
0.2
0.1
c www.webis.de 2011
Cross-language Explicit Semantic Analysis (CL-ESA)
Alan Turing was conceived at
Chatrapur, Orissa, India. His father
was a member of the Indian Civil
Service. He and his wife wanted
Alan to be brought up in England,
so they returned to Maida Vale,
London, where Alan Turing was
born on 23 June 1912. He had an
elder brother, John. His father's
civil service commission was still
active, and during Turing's
childhood years his parents
travelled between Hastings,
England and India, leaving their
two sons to stay with a retired
Army couple. Very early in life,
Turing showed signs of the genius
he was to later prominently display.
4
Turings Vater Julius Mathison
Turing, ein britischer Staatsdiener
in Chatrapur, Indien, und dessen
Frau Ethel wollten, dass ihr Kind in
Großbritannien geboren wird.
Deshalb kehrten sie nach
London-Paddington zurück, wo
Alan Turing am 23. Juni 1912 zur
Welt kam. Da der Staatsdienst
seines Vaters noch nicht beendet
war, pendelte dieser während
Turings Kindheit zwischen England
und Indien. Seine Familie ließ er
aus Furcht vor Gefahren in der
britischen Kolonie bei Freunden in
England zurück. Schon in frühester
Kindheit zeigte sich die hohe
Begabung und Intelligenz Turings.
5
...
...
ϕ
1
0
ϕ
ϕ
5
...
1
...
19
...
6
2
ϕ
0.2
Sprachübergreifende
Ähnlichkeit
0.1
...
...
0.2
3
2
...
0.1
...
...
2
2
c www.webis.de 2011
Cross-language Explicit Semantic Analysis (CL-ESA)
Experimente
1. Sprachübergreifendes Ranking
2. Bilinguale Rangkorrelation
3. Sprachübergreifende Ähnlichkeitsverteilung
4. Tradeoff Effektivität und Effizienz (Dimensionalität)
5. Multilingualität (Zahl gleichzeitig repräsentierbarer Sprachen)
6. Laufzeit
20
q
Vergleich mit zwei State-of-the-Art-Modellen
q
Verwendung zweier multilingualer Testkollektionen
q
Vergleich auf 6 Sprachpaarungen
q
> 100 Millionen Ähnlichkeiten berechnet
c www.webis.de 2011
Cross-language Explicit Semantic Analysis (CL-ESA)
Sprachübergreifendes Ranking
Multilingualität
1
105
105
104
Dimensionen
Recall
0.8
103
0.6
0.4
10
2
0.2
0
2
3
4
5
10
20
Rang des vergleichbaren Dokuments
21
103
102
10
Dimensionen: 10
1
104
50
0
en +fr +pl +ja +nl +it +pt +es +sv +ru +zh +no +fi +vo
+de
Sprachen in der Schnittmenge
c www.webis.de 2011
Wie Maschinen Plagiate erkennen
22
c www.webis.de 2011
Wie Maschinen Plagiate erkennen
q
Wie können sprachübergreifende Plagiate erkannt werden?
q
Wie verlässlich sind Algorithmen zur Plagiatserkennung?
Dokumentkollektion
Verdächtiges
Dokument
Kandidatenretrieval
Kandidatendokumente
Erkennung von Plagiaten
Detaillierter
Vergleich
Wissensbasierte
Nachverarbeitung
Verdächtige
Passagen
23
c www.webis.de 2011
Wie Maschinen Plagiate erkennen
q
Wie können sprachübergreifende Plagiate erkannt werden?
q
Wie verlässlich sind Algorithmen zur Plagiatserkennung?
1 Korpus von Plagiaten
Dokumentkollektion
Verdächtiges
Dokument
Kandidatenretrieval
Kandidatendokumente
Erkennung von Plagiaten
Detaillierter
Vergleich
Wissensbasierte
Nachverarbeitung
Verdächtige
Passagen
3 Alternative Implementierungen
24
2 Erfolgsmaße
c www.webis.de 2011
Studie zur Evaluierung von Plagiatserkennungsalgorithmen
Evaluierungsaspekt Text Code
À Korpusakquise
Verfügbares Korpus
Eigenes Korpus
Á Erfolgsmaße
20%
80%
Korpusgröße [# Dokumente]
[1, 10)
11%
[10, 102)
19%
[102, 103)
38%
[103, 104)
8%
[104, 105)
16%
[105, 106)
8%
25
Evaluierungsaspekt Text Code
18%
82%
10%
30%
33%
11%
4%
0%
Precision, Recall
Manuell, Ähnlichkeit
Laufzeit
Andere
43%
35%
15%
7%
18%
69%
1%
12%
 Vergleichende Experimente
Keine
Parameter
Andere Algorithmen
q
205 Papiere wurden analysiert
q
Ist es möglich, eine Trendwende herbeizuführen?
46%
19%
35%
51%
9%
40%
c www.webis.de 2011
Internationaler Wettbewerb zur Plagiatserkennung
q
Erste standardisierte Testumgebung
q
Ausgerichtet jährlich seit 2009
À Große neue Korpora von Plagiaten (PAN Plagiarism Corpus 2009-2012)
Á Maßgeschneiderte Erfolgsmaße (Plagdet, Precision, Recall, Granularity)
 32 teilnehmende Forschergruppen (35 Anmeldungen für 2012)
26
c www.webis.de 2011
: Korpuskonstruktion
Ziel:
q
Eine möglichst große, repräsentative Auswahl von plagiierten Dokumenten
sowie den verwendeten Quelldokumenten.
Probleme:
q
Reale Plagiatsfälle nicht im großen Maßstab verfügbar
q
Abhängige Variablen unbekannt
Möglichkeiten:
q
Plagiate automatisch generieren
(seit 2009 im PAN Plagiatskorpus)
q
Plagiate halbautomatisch generieren
q
Plagiate manuell erstellen
q
Ähnliche Textwiederverwendungen anderer Domänen sammeln
q
Reale Plagiate suchen / sammeln
(seit 2010 via Mechanical Turk)
(seit 2012 via oDesk)
(seit 2011 für deutsche Dissertationen)
Ü Crowdsourcing als Schlüssel für große Skalen, Realismus und Diversität
27
c www.webis.de 2011
Zusammenfassung & Fazit
Sprachübergreifende Textähnlichkeit
q
CL-ESA benötigt keine Wörterbücher, parallele Korpora, oder Übersetzer
q
Vergleichbare Korpora sind für viele Sprachpaarungen leicht erstellbar
Evaluierung von Plagiatserkennungsverfahren
q
Ergebnisse von PAN zeigen, dass noch viel Luft nach oben ist
q
Das beste, was ein Plagiatserkenner in der Praxis leisten kann ist, das
Durchkommen mit plumpen Plagiaten schwieriger zu machen
q
Eigentlich werden nicht Plagiate, sondern bloß verdächtige
Textwiederverwendungen erkannt
Wettbewerb zur Plagiatserkennung
28
q
Webseite:
http://pan.webis.de
q
Korpora:
http://www.webis.de/research/corpora
q
Community: http://groups.google.com/group/pan-workshop-series
c www.webis.de 2011