Virtual and actual: Relative accuracy of on-site and web-based instruments in auditing the environment for physical activity

Abstract

Objectives To assess the relative accuracy and usefulness of web tools in evaluating and measuring street-scale built environment characteristics. Methods A well-known audit tool was used to evaluate 84 street segments at the urban edge of metropolitan Boston, Massachusetts, using on-site visits and three web-based tools. The assessments were compared to evaluate their relative accuracy and usefulness. Results Web-based audits, based-on Google Maps, Google Street View, and MS Visual Oblique, tend to strongly agree with on-site audits on land-use and transportation characteristics (e.g., types of buildings, commercial destinations, and streets). However, the two approaches to conducting audits (web versus on-site) tend to agree only weakly on fine-grain, temporal, and qualitative environmental elements. Among the web tools used, auditors rated MS Visual Oblique as the most valuable. Yet Street View tends to be rated as the most useful in measuring fine-grain features, such as levelness and condition of sidewalks. Conclusion While web-based tools do not offer a perfect substitute for on-site audits, they allow for preliminary audits to be performed accurately from remote locations, potentially saving time and cost and increasing the effectiveness of subsequent on-site visits.

Applying Google Maps and Google Street View in criminological research

“…A number of public health studies have already looked into the opportunities that Street View offers for collecting data on the built environment, and confirm that audits using Street View imagery offer a convenient and reliable alternative to on-site audits (Wilson and Kelly 2011;Wilson et al 2012;Kelly et al 2013;Ben-Joseph et al 2013;Odgers et al 2012;Badland et al 2010;Clarke et al 2010;Taylor et al 2011;Rundle et al 2011;Griew et al 2013;Kronkvist 2013). The results obtained through Street View are generally valid and consistently show acceptable levels of reliability.…”

“…In general, their results suggest that virtually auditing a particular neighborhood is a reliable, cost-and time-effective alternative to actual on-site visits (cf. inter alia Ben-Joseph et al 2013;Badland et al 2010;Clarke et al 2010).…”

“…They allow a researcher to precisely define the theoretically relevant variables, and assess the reliability and validity of the measures. However, large-scale projects are often unfeasible (for a notable exception see Sampson and Raudenbush 1999) because of the costs and time required to travel to the study area and conduct the audit (Rundle et al 2011;Ben-Joseph et al 2013). Moreover, residents may perceive such audits as invasive (Caughy et al 2001).…”

“…The major disadvantage of using Street View in environmental audits is that small-scale items, such as the presence of cigarette butts or the condition of sidewalks, cannot be reliably measured, and more qualitative assessments relating to the social environment, such as the general level of social disorder, are not accurately assessed (Kelly et al 2013;Ben-Joseph et al 2013;Wilson et al 2012;Odgers et al 2012;Rundle et al 2011;Clarke et al 2010;Griew et al 2013;Kronkvist 2013). Moreover, it is often unclear whether the images accurately reflect the current on-site situation.…”

“…This is especially true for environmental features that are subject to temporal variability (Coupe and Blake 2006;Nee and Taylor 2000;Fujita 2011), such as shrubbery and hedges, the presence of cars on the street and driveway, and whether shutters are closed or lights around the house are on. Finally, the quality of the images sometimes prohibits reliable assessments of detailed features of the built environment (Ben-Joseph et al 2013;Badland et al 2010;Taylor et al 2011;Kronkvist 2013).…”