|Trigger event||The National Map Corps project became available nationwide.|
|Domain||Generic mapping [Structures data are in the public domain and are used to update The National Map geospatial databases and US Topo maps].|
|Organization||US Geological Survey (USGS), National Geospatial Program.|
|Actors||Public, local, state and federal agencies including the USGS.|
|Data sets||USDA National Aerial Imagery Program (NAIP) imagery, National Map base layers, ESRI world imagery, Alaska community photos, the national structures database and US Topo maps.|
|Process||Using crowdsourcing techniques, the USGS’s National Map Corps the US Geological Survey’s (USGS) Volunteered Geographic Information (VGI) project known as “The National Map Corps (TNMCorps)” encourages citizen volunteers to collect and edit data about man-made structures to provide accurate and authoritative spatial map data for the USGS National Geospatial Program’s (http://www.usgs.gov/ngpo/) web-based The National Map.|
|Feedback||Updated structures are contributed in real-time. Databases are updated in near real-time.|
|Goal||Maximize limited resources while continuing to support the National Geospatial Program by leveraging volunteers with local knowledge to update The National Map and USTopo maps. Data collected is in the public domain and freely downloadable.|
|Contact point||Erin Korris, ekorris[at]usgs.gov , Elizabeth McCartney, emccartney[at]usgs.gov or email@example.com.|
VGI is not new to the USGS, but past efforts were hampered by available technologies. Over the last two decades, the USGS has sponsored various forms of volunteer map data collection projects, including the Earth Science Corps where volunteers annotated topographic paper maps, the collection of GPS points using handheld GPS devices and, finally, web-based technology to input data in 2006. In spite of these efforts, and as valuable as the updates were, technology could not keep pace with decreasing USGS resources and changing priorities, and the VGI effort was suspended in 2008. In 2010 – 2012, the perfect storm of improved technology, social media and continued decreasing resources once again made crowdsourcing an attractive option.
After several pilot projects to determine the viability of bringing back the volunteer mapping program, The National Map Corps volunteers are successfully editing 10 different structure types in all 50 states, including schools, hospitals, post offices, police stations and other important public buildings. Using National Agricultural Imagery Program (NAIP) imagery as the primary base layer, volunteers collect and improve data by adding new features, removing obsolete points and correcting existing data. Edits are contributed through a web-based mapping platform and are incorporated into The National Map geospatial databases and ultimately US Topo maps.
Data quality is a common common concern regarding VGI. In order to address those concerns, an analysis of a pilot project over the state of Colorado was conducted in 2012, and a national data quality study was conducted in 2014. For all structure feature types, volunteer involvement was found to improve positional accuracy, attribute accuracy and reduce errors of omission. The studies demonstrated that volunteer edits improve baseline structures data; that further review by advanced volunteers willing to provide peer review improves the data further; and that sample-based inspection by USGS personnel can monitor these processes.
TNMCorps volunteers continue to support the NGTOC mission of the “acquisition and management of trusted geospatial data, services, and map products for the Nation.” After TNMCorps project fully expanded to all 50 states late in FY2013, the project continued to grow. In 2014, a national data quality study was conducted which showed that volunteers were continuing to provide high quality data even as the project expanded from a volunteer corps consisting primarily of GIS students and professionals to the general public. By the end of the first quarter of FY17, over 230,000 points had been edited.
Successful crowdsourcing is not without challenges, some of which include volunteer recruitment, volunteer engagement and participant motivation. The National Map Corps endeavors to meet these challenges using gamification techniques and a mixture of traditional and social media. Gamification includes easy on-ramping, virtual recognition badges, friending, map challenges, social media interaction and a tiered editing approach. Using these techniques has been successful. The National Map Corps continues to see substantial increases in the number of volunteers and volunteer contributions to The National Map.
Other challenges continue to exist and include: organizational resistance to accepting data from volunteers as being “good enough” to populate national databases; and working through issues for which there is no well-established policy regarding government accepting data from citizens. One example is the requirement to obtain approval for conducting a “survey” from the Office of Management and Budget as part of the Paperwork Reduction Act even though the project really is not conducting a “survey”.
The National Map Corps has shown that volunteers can effectively contribute to the quality of structures data shown on The National Map and US Topo maps. Key factors to successful crowd-sourcing include building on past experience, leveraging existing technology, and having the support of key individuals within the organization.
- Adoption of challenging techniques such as gamification has been successful and attracts volunteer interest.
- Evaluation of the quality indicated that the participation improves accuracy and reduces errors.
- Organizational resistance to accepting data from volunteers is one of the major challenges for VGI projects of this kind.
- Key factors to successful crowdsourcing include building on past experience, leveraging existing technology and having the support of key individuals within the organization.