Crowdsourcing and Volunteered Geographic Information

Crowdsourcing and VGI (volunteered geographic information) have been described by one commentator as “more than a threat to the surveying community” and a “challenge for our community.” Another expert has asked, “How is crowdsourcing an application of benefit to surveying,” and asks if it is really the crowd or if it “should be thought of as a collection of amateur volunteers.”

FIG publication #73, New Trends in Geospatial Information: The Land Surveyor Role in the Era of Crowdsourcing and VGI, a report of FIG Commission 3, addresses these questions and more. The publication offers a definition of crowdsourcing as “… the act of taking a job traditionally performed by a designated agent … and outsourcing it to an undefined, generally large group of people in the form of an open call.” An example given is a mapping project in Amsterdam showing bicycle routes through the streets and parks of the city. Thus, a transportation system was identified and defined by citizen users, “the large group of people,” for the benefit of a surveyor/mapper, the “designated agent.” Geographic information was defined by volunteers with a saving of time and effort by the professional surveyor.

The intent is to capture ‘authoritative’ spatial data “in order to achieve goals whether by ‘saving money’, ‘saving time’, or ‘saving lives’”. A few of the suggested tasks for the application of VGI methods are transportation mapping, hydrographic mapping, zoning, planning and land cover mapping and so on. A somewhat more controversial category from the perspective of the American surveyor is the “compilation of draft cadastral maps for the adjudication of parcels and property owners and for other land management and administrative purposes…” However, the report recognizes that “land surveyors are the experts to identify the methods and tools…” and “are not expected to compromise their professional reputation by using unverified data.” Clearly, verification of volunteered data will be of greatest concern to the professional surveyor.

The report discusses conceptual, organizational, fiscal, technical and legal aspects that readers will find informative and logical, while including a few intriguing observations by experts in the field, for instance the example of cadastral surveyors who were “willing to be pragmatic rather than stick strictly to historic methods and high levels of accuracy” in certain countries with developing market economies. The assertion is that the few geographical errors in positioning of properties has “virtually no impact on the functioning of the property market,” an arguable assertion from the point of view of the American property surveyor.

The most logical subjects for crowdsourcing and VGI application by surveyors are those spatial data subjects whose dimensions and positions are minimally definitive. Typical subjects could be acoustical levels of noise in urban neighborhoods; distribution of tree species in Central Park; available parking spots in municipal zones; urban escape routes for emergency response and the like, any or all of which would be transferred to the surveyor’s base mapping. Collections of statistics on these spatial data could be organized by the surveyor who would also provide training for citizen volunteers and systems for verification at acceptable levels of accuracy. Recruiting and enlistment of the citizen volunteers might be a task for the surveyor or perhaps best accomplished by the client or organization for which the survey is being performed.

For many American surveyors accustomed to taking full professional responsibility for the information displayed on their maps and plans, this will all come as a revolutionary, even potentially perilous service, and one more example that the profession is changing not only in the adaptation of new technologies but in the very form of the services we provide.

Robert W. Foster, PS, PE, of Hopkinton, MA, is in private practice, offering professional consulting services nationally in arbitration, dispute resolution and litigation involving surveying and civil engineering issues. He is past president of the International Federation of Surveyors (FIG).