Geographic Web Information Retrieval

1
Geographic Web Information Retrieval

• Alexander Markowetz, University of Marburg
• Thomas Brinkhoff, FH Oldenburg
• Bernhard Seeger, University of Marburg

2
Current Situation In Web-IR

• Everybody is online
• But never seen

3
Current Situation In Web-IR

• Queries are too short
• Resultsets are too large

• You can effectively block your competitors
• Good results get buried

• Smaller Results
• Ways to drill the ice-berg

4
Solutions

• Personalized Search
• Dynamic/Interactive Search

5
Geographic Web-IR

• Location is the most personal property
• All business is local
• People already use the web geographically
• Yoga Brooklyn
• Linux usergroup Frankfurt
• And get poor results
• We are going to make that a lot better

6
How-Not-To

• Semantic Web
• If just everybody included Geographic Markup in
  their web-pages
• Two problems
• Chicken-Egg
• Malicious Webmaster
• Metatags Anyone?
• Bottomline
• Semantic web is for B2B situations only.

7
How-To

• Modify traditional IR techniques to extract
  geographic markers
• Multigranular approach
• Extending basic Web-IR
• Map pages to geographic positions
• Footprint
• Aggregate and Cluster them
• Build Applications
• Geographic Search
• Geographic Web-Mining

8
Geocoding

• Footprint
• Geographic Position of a Webpage
• Set of points and polygons, associated with some
  amplitude

9
Preliminaries

• Basic IR Assumptions can easily be extended to
  geographic-IR
• Radius-1 Hypothesis
• Radius-2 Hypothesis (co-citation)
• Intra-Site Hypothesis
• Intra-subdomain
• Intra-directory

10
Multigranularity

• Information extraction on different levels
• Domain
• Subdomain
• Directory
• File
• Need to aggregate

11
Sources

• On all levels
• Names of places
• Zip-codes
• Area-codes
• On Site Level
• Whois
• Business Directories
• Links
• Density over a given area
• Radius-1 and Radius-2

• Geospatial Mapping and Navigation of the Web,
  Kevin S. McCurley, 10th WWW, 2001
• Computing Geographical Scopes of Web Resources,
  J. Ding, L. Gravano, and N. Shivakumar, VLDB 2000

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Geographic Search

• SEARCH

• A simple interface
• Not so exciting, but...

13
Dynamic Geographic-IR

• Replacing the next button

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Locality

• Final ranking is a (linear) combination of
  importance and geographic distance.
• Chances are
• Amazon will still rank first no matter where you
  are
• Amazon is a global bully
• Idea
• Eliminate global bullies by computing importance
  differently
• Give less weight to links that span a longer
  distance

15
Evaluation

• Evaluation Web-IR is hard
• Evaluating geo-Search is even harder
• Mistakes are hard to find

16
Impact of geo-IR

• Next generation Search Engine
• Location based Service
• For cellphones under UMTS
• Move traffic from AE
• Local companies will get more traffic
• Increase Profits from Adwords
• Smallest businesses will advertise online
• Locally focused
• The Leaflet-industry will shrink

17
Geographic Web-Mining

• The web reflects human society.
• Distorted
• Delayed/Ahead
• A lot of interesting social questions can be
  answered by looking at a large webcrawl
• You can save time and money compared to
  door-to-door surveys
• This is widely used
• But
• Most of them are of geographic nature

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Example Queries

• Where in Germany are vintage sneakers a trend?
• Is there a fashion authority that is accepted in
  all regions of Germany?
• Do Britney and Madonna have the same audience?

• Draw a map of Germany with all sites about
  vintage sneakers.
• Find all fashion-sites that get a min of 1000
  equally distributed links.
• Map the areas in Germany, where there are
  significantly more Sites for B. than for M.

• Precise Semantics?

19
Current Work

• Older Prototype
• Metasearch on top of lycos.de
• Screen-scrape re-order
• Whois only
• Did very well

20
Current Work

• Current Prototype for Geographic Search
• Limited to Germany .de domains
• 50.000.000 Pages
• Expected online by late summer
• In co-operation with
• Yen-Yu Chen
• Xiaohui Long
• Torsten Suel
• Polytechnic University, Brooklyn

21
Reinventing Web-IR

• Nearly no (academic) work in geo-IR
• Allmost every aspect of Web-IR needs to be looked
  at again
• Interfaces
• Query processing
• Index distribution
• Link analysis
• User profile analysis
• Spam detection
• Even
• Other aspects of personalized search
• Changes in the web

22
Thank you

• Any questions?