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Social Geography & Wikipedia a quick overwiew
 

Social Geography & Wikipedia a quick overwiew

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A quick overview about the topic of geodata and crowdsourcing

A quick overview about the topic of geodata and crowdsourcing

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    Social Geography & Wikipedia a quick overwiew Social Geography & Wikipedia a quick overwiew Presentation Transcript

    • Social Geography & Wikipedia a quick overwiew Maurizio Napolitano (SoNet internal research meeting) FBK 27/08/2010
    • SoNet Research Meetings These slides were used for an internal presentation of the SoNet group. Every week, one member of the SoNet group presents a research papers to the other members. The mentioned paper(s) are hence written by other researchers. Being internal presentations, these slides might be a bit rough and unpolished. You can find more information (including this presentation) about the SoNet group at http://sonet.fbk.eu
    • Summary • Introduction: the wikification of GIS • Wikipedia and geodata • Some research questions – You Are Where You Edit: Locating Wikipedia Contributors Through Edit Histories – Spatiotemporal Mapping of Wikipedia Concepts
    • Introduction
    • Introduction Sui, D.Z. The wikification of GIS and its consequences: or Angelina Jolie's new tattoo and the future of GIS. Comp. Env. Urb. Sys. 2008, 32, 1-5.
    • The wikifications • The GIS has changed – Better hardware → easy management – Data production → Crowdsourcing project (WikiMapia, OpenStreetMap, Mapufacture, GeoCommons, TierraWiki, FixMyStreet, WhoIsSick … ) and GeoTag – People → Organizations … NEOGEOGRAPHY ...
    • Wikipedia and geodata – applications (1/2) • Space-time exploration • Space-time selection • Space-Wikipedia relationship exploration • Space-Wikipedia relationship selection Hecht, B.; Rohs, M.; Schöning, J.; and Krüger, A. 2007. WikEye - using magic lenses to explore georeferenced Wikipedia content. In Proc. of the 3rd International Workshop on Pervasive Mobile Interaction Devices.
    • Wikipedia and geodata – applications (2/2) Spatial feature-edge-feature relationships in Wikipedia Berlin article temporal reference profile
    • Wikipedia e geodata
    • Wikipedia geopages – the infobox {{Infobox Settlement … |latd = 37 |latm = 18 |lats = 15 |latNS = N |longd = 121 |longm = 52 |longs = 22 |longEW = W … }} You Are Where You Edit - Michael D. Lieberman - ICWSM 2009, San Jose, CA
    • Wikipedia geopages – problem and solution Must process page Wiki markup to identify DBpedia geographic templates and – Public ontology derived extract coordinates from Wikipedia, including – Wiki markup language extracted geographic continually evolves coordinates – Geographic templates – Amounts to a primitive continually evolve gazetteer of geographic – Over 20 distinct template forms entities in Wikipedia at this time for different coordinate systems and feature types
    • Features With Extent All geopages are tagged with a single lat/lon point Tradeoff between simplicity and accuracy Examples: Country or state  Center or capital city, Road  Midpoint, River  Source Want to distinguish these features, as tagged point may be geographically distant from other contributor edits In Wikipedia, more precise coordinates generally indicates smaller extent California: (37, -120) San Jose, CA: (37.304, -121.873)
    • Some research questions 1. You Are Where You Edit 2. Spatiotemporal Mapping of Wikipedia Concepts
    • You Are Where You Edit: Locating Wikipedia Contributors Through Edit Histories • Contributors tend to add what they know and self- organize into groups based on interest – Can contributors be further categorized based on their edits to geographic pages? (= geopages) • Identify Wikipedia contributors who: – Edit geopages in a constrained geographic area – Mostly edit one or two “pet” geopages – Identify reasons for the above patterns Worked only on the english Wikipedia version 8 Oct 2008 - 61.7GB of data. You Are Where You Edit - Michael D. Lieberman - ICWSM 2009, San Jose, CA
    • Wikipedia/DBpedia dump statistics. Stat Type Class Total Geo Geo% pages 14915993 328393 2.2% contrib both 16235895 2011828 12.4% anon 13795118 1655135 12.0% named 2440777 356693 14,6% edits both 224473397 15341937 6.8% anon 55571407 4519807 8.1% named both 168901990 10822130 6.4% non minor 114844836 6357558 5.5% minor 54057154 4464572 8.3% A considerable number of pages (~330k) are tagged with geographic coordinates
    • Basic Observations • Named contributors are outnumbered by anonymous ones by about 5 to 1, but are responsible for 2–3 times as many geopage edits • A nontrivial number of named contributors have made at least one non-minor edit to a geopage (14.6%) • Most edits to geopages are non-minor edits (58.7%)
    • Geopages Country distribution Country Count • Vast majority of USA 83871 geopages tagged to France 37730 the US and Europe UK 26651 • Possibly reflects the Poland 16050 Germany 15939 geographic Russia 10964 distribution of Canada 8970 contributors to the Italy 8772 English Wikipedia Spain 6603 India 5683 You Are Where You Edit - Michael D. Lieberman - ICWSM 2009, San Jose, CA
    • Wikipedia geocoverage - en.wikipedia.org
    • Wikipedia Edit Histories • Easily-parsed XML format • Information saved for each edit: – Username (or IP address, if anonymous) – Timestamp – Whether edit is “minor” (spelling, formatting) • Excluded anonymous edits – Not allowed to be marked minor, to avoid abuse – Most Wikipedia vandalism perpetrated anonymously • Also excluded minor edits – Geopages tend to have mostly non-minor edits
    • Sample Edit Patterns
    • Indentify edit area contributors • Large number of edits to geopages • Geopage edits constrained to a small area • At least K edited geopages • Area α of convex hull of edited geopage coordinates smaller than A (edit area) Of 356693 contributors with at K = 3 and - A = 1 deg2 ≈ 112 x 112 km least one edit to a geopage, only 102271 (28.7%) have user pages. Also, for the 93195 contributors with at least five edits to geopages, only 47623 (51.1%) have user pages.
    • Accounting For Outliers • Local edit patterns may be muddled by “outlier” edits • For each contributor, select a fraction F of edited geopages with smallest convex hull area • Simple approximation scheme: 1. For each geopage P: a. Sort edited geopages by distance from P b. Compute convex hull HP of first F geopages 2. Select HP with smallest area α • Example: 71 deg2 - 10 deg2 (5k x 5k mi - 112 x 112km)
    • Contributor Locality Computed minimum edit area sizes for F = {95%, 80%}, both (a) with and (b) without features with extent 30–35% of contributors have edit areas smaller than 1 deg2 Over 50% of contributors with less than 5 geopage edits are highly local
    • Pet Geopages • Statistics for users with: – 5–20 edits (~93k) – over 20 edits (~28k) • Over 50% of contributors with 5–20 edits, and 25% of contributors with over 20 edits, have over 80% of geopage edits confined to two geopages
    • Reasons for Tight Edit Areas Randomly selected 100 contributors with at least 10 edits to geopages and small edit areas • Concurrently examined contributors’ user pages and the set of edited geopages to determine an interest • Contributors with small edit areas tend to be born in or are living in the region defined by their edit areas
    • Some research questions 1. You Are Where You Edit 2. Spatiotemporal Mapping of Wikipedia Concepts
    • The question “Where” and “when” are important implicit aspects of a wide variety of concepts. Wikipedia offer: . Geopages – . Biography (birth and death dates) – . Temporal and spatial information concerning concepts – (Romanticism, Scholasticism) HOW ASSOCIATE THIS INFORMATION? The solution start by using dbpedia By using common wiki pages in this languages: English, German, French, Italian, Spanish, Dutch and Portuguese.
    • Results about spatiotemporal mapping of Wikipedia concepts Topics explorerd: 1.Concepts and geolocation 2.Biography and country 3.Cultural interaction between countries 4.Historical periods of literature and philosophy and related countries
    • Country rappresented in Wikipedia geopages Distribution of geotagged articles in different countries (log2 values are plotted).
    • Top 20 cities (geotagged) 14.000 total Top 20 cities by number of geotagged articles.
    • People by century Distribution of Wikipedia person articles per century of lifespan. Log2 values are shown. The total number of century-people associations is higher than 423,846 because many persons are associated with 2 centuries
    • Biography and countries Distribution of Wikipedia biographies by nationality
    • Distribution of Wikipedia biographies by occupation
    • Cultural interactions Top 5 source (incoming) and destinations (outgoing) of cultural interactions for 10 countries. Statistics computer from the study of locations associated to persons present in Wikipedia. The size of displayed countris is proportional to the log2 of the contry's score.
    • Top 5 cities and countries in philosophy for different periods Top 5 cities and countries in philosophy for different periods. Starting with the 1st century, five century slots were used.
    • Top 5 cities and countries in literature from the 15th century to nowadays. One century time slots were usede
    • Creative Commons Attribution-ShareAlike 2.5 You are free: ● to copy, distribute, display, and perform the work ● to make derivative works ● to make commercial use of the work Under the following conditions: Attribution. You must attribute the work in the manner specified by the author or licensor. Share Alike. If you alter, transform, or build upon this work, you may distribute the resulting work only under a license identical to this one. For any reuse or distribution, you must make clear to others the license terms of this work. Any of these conditions can be waived if you get permission from the copyright holder. Your fair use and other rights are in no way affected by the above. More info at http://creativecommons.org/licenses/by-sa/2.5/ All the images come from the relative papers
    • Bibliography Sui, D.Z. The wikification of GIS and its consequences: or Angelina Jolie's new tattoo and the future of GIS. Comp. Env. Urb. Sys. 2008, 32, 1-5. http://geog.tamu.edu/~sui/publication/pub2008/SuiCEUSeditorial.pdf Hecht, B.; Rohs, M.; Schöning, J.; and Krüger, A. 2007. WikEye - using magic lenses to explore georeferenced Wikipedia content. In Proc. of the 3rd International Workshop on Pervasive Mobile Interaction Devices http://www.deutsche-telekom-laboratories.de/~rohs/papers/Hecht-WikEye.pdf Michael D. Lieberman You Are Where You Edit ICWSM 2009, San Jose, CA http://www.umiacs.umd.edu/~jimmylin/publications/Lieberman_Lin_ICWSM2009.pdf Adrian's analysis of Wikipedia: Adrian Popescu, Gregory Grefenstette Spatiotemporal Mapping of Wikipedia Concepts, JCDL 2010, June 21 - 25, Brisbane, Australia http://portal.acm.org/ft_gateway.cfm?id=1816142&type=pdf