Participatory Mapping and Participatory Mapping and Participatory Mapping and Volunteered Geographic Information Participatory Mapping and Volunteered Geographic Information Seth Peery, Sr. GIS Architect Social Media for Planning April 22, 2011 Virginia Tech Geospatial Information Sciences
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Participatory Mapping andParticipatory Mapping and ...Participatory Mapping andParticipatory Mapping and Volunteered Geographic Information Seth Peery, Sr. GIS Architect Social Media
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Participatory Mapping andParticipatory Mapping andParticipatory Mapping and Volunteered Geographic InformationParticipatory Mapping and Volunteered Geographic InformationSeth Peery, Sr. GIS Architect
Social Media for Planning April 22, 2011Virginia Tech Geospatial Information Sciences
OverviewOverviewOverviewOverview• Overlaps between GIS and “social media”
• Participatory Mapping and Citizen Sciencep y pp g• Public Participation GIS• Volunteered Geographic Information• Mashups and Web Servicesp
• Applications• Popular examples• Virginia Tech participatory mapping projectsVirginia Tech participatory mapping projects
• Best practices • Design considerations for collecting data from the public• Validity and use of VGI• Validity and use of VGI
Economic Development ResearchEconomic Development Research
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Designing Interfaces for VGIDesigning Interfaces for VGIDesigning Interfaces for VGIDesigning Interfaces for VGI• CONSTRAIN USER INPUT as much as possible!• List boxes are preferable to free-form text• Collect as much metadata as you can (IP, timestamp, zoom level, other map
variables) for later filtering use• “Users are evil” – protect against SQL injection (but also junk data)… validate,
validate!• Decide on level of isolation between the users and the data
– Writing directly to production – Writing to a staging DB
Human approval required first (Moderation)– Human approval required first (Moderation)• All VGI is spatial, but not all VGI is GIS – ESRI stack vs. traditional DBs (e.g.,
MySQL)• Protection of PII (and… getting useful data vs. getting a usefully large sample
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size)• Spatial unit of VGI – smaller is better
Data Ingestion and AnalysisData Ingestion and AnalysisData Ingestion and AnalysisData Ingestion and Analysis• Workflow depends on research questions and software platform for
analysis• Data may have been collected in different format than required for
analysis• For GIS, we can ingest csv/txt as XY data – more direct import into
SAS/SPSS/R/etcSAS/SPSS/R/etc.• Need to eliminate outliers and obvious errors – use as much metadata
as you can – but note impacts of doing this on sample size• Spatial generalization points to polygons averages sums• Spatial generalization – points to polygons, averages, sums.• Suitability for interpolation?• Mapping underlying pattern vs. mapping the distribution of
responsesresponses
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Validity ThreatsValidity ThreatsValidity ThreatsValidity Threats• VGI/geospatial crowdsourcing methodologically similar to a survey instrument• Sampling bias – spatial/other• Precision/accuracy of VGI spatial data• Correctness of attribute data (assertion)• Credibility of VGI [1] y
• Authority vs. credibility• Uniqueness, situation, formal training• Perception of accuracy and provenance
• User input mistakes vs systematic abuse (astroturfing)• User input mistakes vs. systematic abuse (astroturfing)• Identification and filtering of outliers• Uncertainty and how to quantify it
[1] Flanagin, A. J. and M. J. Metzger (2008). "The credibility of volunteered geographic information." GeoJournal 72: 137.
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Contact InformationContact InformationContact InformationContact Information
Seth PeerySeth PeerySenior GIS Architect, Enterprise GISVirginia Tech Geospatial Information Sciences2060 Torgersen Hall (0197), Blacksburg, VA 24061(540) 231-2178sspeery@vt [email protected]://gis.vt.edu