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 Dir File Dom SDom Dir File

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, 10 th WWW, 2001 Geospatial Mapping and Navigation of the Web  Computing Geographical Scopes of Web Resources, J. Ding, L. Gravano, and N. Shivakumar, VLDB 2000 Computing Geographical Scopes of Web Resources Dir File Dom SDom Dir File

12 Geographic Search  A simple interface  Not so exciting, but...  Key Words  City  Street  State  Area code  SEARCH

13 Dynamic Geographic-IR  Replacing the „next“ button  Closer  Continue  Wider  Next  Closer  Wider  Next  ½ mile  1 mile  2 miles  5 miles  10 miles  25 miles 100 miles

14 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 A&E  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

18 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  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?