Undue Influence: Eliminating the Impact of Link Plagiarism on Web Search Rankings

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Undue Influence Eliminating the Impact of Link
Plagiarism on Web Search Rankings

• Baoning Wu and Brian D. Davison
• Lehigh University
• Symposium on Applied Computing 2006

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Motivation

• Link-based ranking algorithms are important to
  current popular search engines. (e.g., HITS for
  Teoma)
• Link farms will deteriorate the performance of
  link-based ranking algorithms

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HITS algorithm

• Each page has two measures, authority score a
  shows how good this page is for a query, hub
  score h shows the possibility that the page
  points to good authority pages. E is the
  adjacency matrix.
• a ET h
• h E a

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Example for query weather

• http//www.tripadvisor.com/
• http//www.virtualtourist.com/
• http//www.abed.com/memoryfoam.html
• http//www.abed.com/furniture.html
• http//www.rental-car.us/
• http//www.accommodation-specials.com/
• http//www.lasikeyesurgery.com/
• http//www.lasikeyesurgery.com/lasik-surgery.asp
• http//mortgage-rate-refinancing.com/
• http//mortgage-rate-refinancing.com/mortgage-calc
  ulator.html

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Factors that degrade HITS

• Mutually reinforcing relationships
• Duplicate pages
• Link farms

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Complete hyperlink

• Definition
• The link with its anchor text as a unit.
• Duplication of a complete link is a much stronger
  sign of copying behavior on the Web than a
  duplicate link target.

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Document - Complete link Matrix
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Bipartite Graph

• Two disjoint sets X and Y, each edge starts from
  an element in X and ends with an element in Y.

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Link farms

• Link farms are usually densely connected via
  multiple overlapping small bipartite cores.
• Task to detect densely connected bipartite
  components from document - complete link matrix

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Algorithm for finding bipartite components
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Result k2 and l2
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Adjustment document-document matrix
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Final matrix
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Weighted adjacency matrix
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Experiment HITS result of rental car

• http//www.discountcars.net/
• http//www.motel-discounts.com/
• http//www.stlouishoteldeals.com/
• http//www.richmondhoteldeals.com/
• http//www.jacksonvillehoteldeals.com/
• http//www.jacksonhoteldeals.com/
• http//www.keywesthoteldeals.com/
• http//www.austinhoteldeals.com/
• http//www.gatlinburghoteldeals.com/
• http//www.ashevillehoteldeals.com/

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Experiment BH HITS result of rental car

• http//www.rentadeal.com/
• http//www.allaboutstlouis.com/
• http//www.allaboutboston.com/
• https//travel2.securesites.com/
• about_travelguides/addlisting.html
• http//www.allaboutsanfranciscoca.com/
• http//www.allaboutwashingtondc.com/
• http//www.allaboutalbuquerque.com/
• http//www.allabout-losangeles.com/
• http//www.allabout-denver.com/
• http//www.allabout-chicago.com/

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Experiment CL-HITS result of rental car

• http//www.hertz.com/
• http//www.avis.com/
• http//www.nationalcar.com/
• http//www.thrifty.com/
• http//www.dollar.com/
• http//www.alamo.com/
• http//www.budget.com/
• http//www.enterprise.com/
• http//www.budgetrentacar.com/
• http//www.europcar.com/

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Experiment BH HITS result of translation
online

• http//www.no-gambling.com/
• http//www.teleorg.org/
• http//ong.altervista.org/
• http//bx.b0x.com/
• http//video-poker.batcave.net/
• http//www.websamba.com/marketing-campaigns
• http//online-casino.o-f.com/
• http//caribbean-poker.webxis.com/
• http//roulette.zomi.net/
• http//teleservices.netfirms.com/

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Experiment CL-HITS result of translation
online

• http//www.freetranslation.com/
• http//www.systransoft.com/
• http//babelfish.altavista.com/
• http//www.yourdictionary.com/
• http//dictionaries.travlang.com/
• http//www.google.com/
• http//www.foreignword.com/
• http//www.babylon.com/
• http//www.worldlingo.com/products_services
• /worldlingo_translator.html
• http//www.allwords.com/

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Duplicate example BH-HITS result of maps

• http//www.maps.com/
• http//www.mapsworldwide.com/
• http//www.cartographic.com/
• http//www.amaps.com/
• http//www.cdmaps.com/
• http//www.ewpnet.com/maps.htm
• http//mapsguidesandmore.com/
• http//www.njdiningguide.com/maps.html
• http//www.stanfords.co.uk/
• http//www.delorme.com/

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Duplicate example CL-HITS result of maps

• http//www.maps.com/
• http//maps.yahoo.com/
• http//www.delorme.com/
• http//tiger.census.gov/
• http//www.davidrumsey.com/
• http//memory.loc.gov/ammem/gmdhtml/gmdhome.html
• http//www.esri.com/
• http//www.maptech.com/
• http//www.streetmap.co.uk/
• http//www.libs.uga.edu/darchive/hargrett/maps/map
  s.html

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User evaluation
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Discussion

• Using link alone, the precision at 10 is 66.4.
  Much lower than using complete link.
• Random anchor texts.

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• Questions?
• baw4_at_cse.lehigh.edu
• davison_at_cse.lehigh.edu