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John Fagan: The Black Art of Geocoding
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John Fagan: The Black Art of Geocoding



John Fagan of Microsoft talks about the challenges of Geocoding in consumer online mapping services

John Fagan of Microsoft talks about the challenges of Geocoding in consumer online mapping services



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    John Fagan: The Black Art of Geocoding John Fagan: The Black Art of Geocoding Presentation Transcript

    • The Black Art of GeocodingFinding that elusive lat/lon
      John Fagan, Microsoft
    • The Black Art of GeocodingFinding that elusive lat/lon
      John Fagan
      Program Manager
      Microsoft Corporation
    • We been making maps for 1000’s of years
    • Well known and established standards/principles
    • Lots of experience in building software to create bitmaps from vector and raster data
    • Data availability & Simple data model
    • Mapping easy to scale
    • ...and so is routing
      1000’s years experience in wayfinding
      Over 50 years experience in routing algorithms
      Dijkstra's shortest path algorithm (1959)
    • Data availability & Simple data model
    • Routing, easy to scale
    • Geocoding not so easy
      20 years experience
      10 years of global Geocoding
      5 years exposing geocoding to the mass consumer
      No standard algorithms
      Very few databases purpose built (maybe GNAF)
      Very hard to scale
    • Geocoding is fundamental
      Cant get a map without a geocode
      Cant get a route without a geocode
      Cant view your data without a geocode
      80% of all information contains a geographic element.
    • It used to be easier
    • Now its hard
    • User expectations change with unstructured input
      67 hill veiw road, s61 2bn in the 1850's
      1.5 hours from Nice
      exact directions from Bangkok Patana School to Suvanapumi Airport in Bangkok.
      10 mile radius from se20 7ua
      how long would it take me to walk around cancun
      how to get to m13 gb from g83 9le by car
      do bearded dragons bite?
    • But ......Geocoding NOT about Search
    • 52.19157,-1.70415
    • The reason it's called 'I'm Feeling Lucky,' is of course that's a pretty damn ambitious goal. I mean to get the exact right one thing without even giving you a list of choices, and so you have to feel a little bit lucky if you're going to try that with one go," tried to explain Sergey Brin.
    • Why is it hard (2 reasons)
    • Parsing: Hard to understand unstructured input
    • Finding Stratford-upon-Avon
      stratford upon avon
      Stratford upon haven
      stratford on avon
      stratford 0n avon
      stratford - upon-avon
      stratford on avaon
      stratford upon aavon
    • Parsing
      In computer science and linguistics, parsing, or, more formally, syntactic analysis, is the process of analyzing a text, made of a sequence of tokens (for example, words), to determine its grammatical structure with respect to a given (more or less) formal grammar.
    • Old way of Parsing – Rules based
      A rules based approach (mainly done with regular expressions)
    • Probabilistic approach
      Machine learned
      Requires you to “train” the engine
      Requires truth sets of training data
    • Probabilistic approach: Hidden Markov Model
      input --> 165 fleet street london EC4A 2DY
      output -->
      address {
      street number : 165
      street : fleet street
      city : london
      postcode : EC4A 2DY
    • Multimap stats
    • Parsing has its limitations
      Parsing failures
      Multimap/Bing Maps (standrewsscotland)
      Google (uk near Boston, MA, USA)
      All fail - House number plus postcode (165, EC4A 2DY)
    • Parsing using a Spatial Engine
    • Why is it hard (Data)
    • Hard to match input with reference database
    • [OSM-talk] Baghdad maps
      I am informed that any road may have up to 4 names (which may be the same or different):
      The pre-Saddam name
      The Saddam-era name.
      The "public" name - What the people who live there call it.
      The "Official" name - What the new Government calls it.
      This situation is further complicated by language and social issues: Language
      The roads are names in Arabic.
      There is no fixed translation between the Arabic and Latin alphabets.
      Social Issues:
      1) Sunnis tend to use the Saddam-era names
      Shia tend to rename streets and won't acknowledge Saddam-era names.
      Ethnic cleansing is changing the neighbourhoods and hence the names.
      Names (such as 14th July Bridge) will change later.
      My translator's opinion is that street names are going to take at least 2-3 years to settle down.
    • Don't throw away your data
      Multimap have always kept old postcodes
      10% of Multimap’s postcode database is of “dead” postcodes
      This might not work for routing and mapping, but very valuable for Geocoding
    • EC4A 1HE – Postcode of vintage 2002
    • Lash data and enrich
    • Future = Real time Geocoding?
    • Summary
      Mapping and Routing – FIXED
      Geocoding – Must Try Harder
    • thanksjohn faganubergeo.com@johnbfagan