PUBLIC PROTECTION AND ETHICAL GEOSPATIAL DATA DISSEMINATIONAN INITIATIVE OF GEOIDE (PROJECT IV-23)

VOLUNTEERED GEOGRAPHIC INFORMATION (VGI) AND COMMUNICATING GEOSPATIAL DATA

QUALITY OF 3D OBJECTS IN VIRTUAL GLOBESKrista Jones1, Rodolphe Devillers1,2, Yvan Bédard2 and

David Coleman3

1 – Dep. of Geography, Memorial University of Newfoundland2 – Dep. of Geomatics, Université Laval

3 – Dep. of Geomatics Engineering, University of New Brunswick

Outline

• Volunteered Geographic Information (Rodolphe)– What is it?– Why is it useful to data producers?– Work done in our GEOIDE project (David Coleman’s team)

• Data quality visualization of 3D VGI (Krista)– Context– Research Problem– Visualization Method & Approach– Perceived Quality– Prototypes & Testing– Future Work – Conclusions

Outline

• Volunteered Geographic Information (Rodolphe)– What is it?– Why is it useful to data producers?– Work done in our GEOIDE project (David Coleman’s team)

• Data quality visualisation of 3D VGI (Krista)– Context– Research Problem– Visualization Method & Approach– Perceived Quality– Prototypes & Testing– Future Work – Conclusions

What is VGI?

• Volunteered Geographic Information (VGI)– Response of the geospatial community to the

“Web 2.0”– Specific type of “User-generated content”– Can be used for “crowdsourcing”

• Citizens (the lay people) produce and share geographic information– E.g. OpenStreetMap, Wikimapia

What is VGI?

Example: OpenStreetMap

Why VGI?

• Many data producers are exploring the possibility to use crowdsourcing to produce geographic information

• “It doesn’t make sense, they are not professionals”– Well, two recent studies (Haklay 2010 and Girres

and Touya 2010) show that OpenStreetMap is generally more accurate than maps from the OS or IGN-France…

VGI

• Number of questions/issues remain:– Completeness (heterogeneous quality)– How can one assess• the reliability of the contributor• the quality of the data produced

– Questions of liability (who is liable?)

Work done in the GEOIDE project(Coleman et al. @ UNB)

To investigate and demonstrate how

…..volunteered contributions of geospatial data from both individual citizens and professional mapping organizations ….

…may be authenticated, processed and employed to populate new public, government and commercial map databases.

Essential Questions

• Why would individuals want to contribute anyway (and what keeps them contributing)?

• What is the authoritative mapping organization's rationale for considering VGI? What mission, objective or problem is being addressed?

• To what extent, if at all, should VGI be adopted?

• How may credible VGI contributors be qualified?

• How may incorrect, misleading or damaging contributions be identified and excluded?

• How much control over content and quality are such organizations prepared to relinquish? Who makes the final decisions regarding the reliability of a given update?

Who are the "Volunteers” in VGI

• Can we characterize them?

• Can we characterize their contributions?

Coleman, D.J., Georgiadou, Y. and Labonte, J. [2009]. "Volunteered Geographic Information: The Nature and Motivation of Produsers." International Journal of Spatial Data Infrastructures Research Vol. 4. http://ijsdir.jrc.ec.europa.eu/index.php/ijsdir/article/view/140/198.

3 VGI Case Studies to Date

• USGS National Map Corps Initiative

• Notification and Editing Service, Dept. Of Sustainability and Environment, State of Victoria, Australia

• TomTom's MapShare™ Service

Coleman, D.J., Sabone, B. and N. Nkhwanana [2010]. "Volunteering Geographic Information to Authoritative Databases: Linking Contributor Motivations to Program Effectiveness". Geomatica Vol. 64, No. 1 pp. 383-396. Special Issue on Volunteered Geographic Information. March.

Follow-on Research @UNB

• Positional Accuracy Assessment of VGI Tools

• Assessing Credibility of Contributors and Reliability of their Contributions

Coleman, D.J. [2010]. " The Potential and Early Limitations of Volunteered Geographic Information". Accepted for publication in Geomatica , Vol.64, No.2. Special Issue on 50th Anniversary of the Department of Geodesy and Geomatics Engineering at the University of New Brunswick. June.

Outline

• Volunteered Geographic Information (Rodolphe)– What is it?– Why is it useful to data producers?– Work done in our GEOIDE project (David Coleman’s team)

• Data quality visualization of 3D VGI (Krista)– Context– Research Problem– Visualization Method & Approach– Perceived Quality– Prototypes & Testing– Future Work – Conclusions

Context - Virtual Globes• Very recent technology/concept

– Al Gore 1998– NASA’s World Wind (2003) & Google Earth

(2005)

• Virtual Globes: Important tool for the democratization of geospatial information

• Integrate 3D data (e.g. city models)

• Users can create, share and view 3D models

World Wind

Google Sketchup

Problem - Heterogeneous Quality of 3D Models

• The quality of user-generated 3D objects can be very heterogeneous

– The level of realism of a model does not always indicate its accuracy

– Novice and expert users can rarely assess the quality of 3D objects

– There are then risks related to decision making based upon these models

Model created by: User 1

Model created by: User 2

Problem – Current Visualization Methods

• The visualization of uncertainty/data quality has been the subject of numerous research projects

• Many methods have been proposed, but none have been used in widespread practice– Complexity – Technical feasibility

Wireframe Transparency

Glyphs

Visualization Method & Approach

Visualization Method & Approach

• Symbiotic Approach– Trade-off to make sure that everything works together as

a whole • “holistic approach”

– Term which refers to the balance between the simplicity and detail of the method

– Richness of visualization vs. ease of understanding

VS

– Technical feasibility

simplicity detail

Visualization Method & Approach

– Amazon.com - visual variable value is used to convey the rating of the product

Visualization Method & Approach

• 5 Star System– Approach inspired by other systems (e.g.

Amazon, EBay, iTunes)– Users can:• Assess the quality on a 1 to 5 rating system• Add more detailed comments

– Assessing appropriate ways to geospatially visualize stars

Perceived Quality

• New concept of "perceived quality" (vs. measured) for geospatial information

• Perception which a user has about the quality of data for their own needs

– By examining a model the user then gauges what the

quality of the dataset is for their personal use based on other users commentary and feedback

Prototypes & Testing

• Tests of representations of stars

– Using various visual variables (size, color, etc.)– Using different geometries for stars (2D vs 3D)

Prototypes & Testing

• Quality slider

• User comments

Prototypes & Testing

• In progress– Representation of stars– Google Earth– Two cities

• San Francisco and Prague• Different urban characteristics for testing of visualization methods

Conclusions

• Developed a symbiotic approach which combines a detailed assessment (feedback) with a simplified display (stars)

• New approach based on users’ perception of quality• Novel way to collect and display quality of 3D objects

in virtual globes• Allows non-expert users to understand the quality of

the data they are using for decision-making• Method usable for any other type of 3D object (not

just buildings)

Acknowledgments

• GEOIDE

• Memorial University of Newfoundland

• Natural Sciences and Engineering Research Council of Canada (NSERC)

• NSERC Industrial Research Chair in Geospatial Databases for Decision Support

Questions?