Research Article

June 2004

Protection of Geoprivacy and Accuracy of Spatial Information: How Effective Are Geographical Masks?

Authors: Mei-Po Kwan, Irene Casas, and Ben SchmitzAuthor information and affiliations

Publication: Cartographica: The International Journal for Geographic Information and Geovisualization

Volume 39, Number 2

https://doi.org/10.3138/X204-4223-57MK-8273

Abstract

Spatial analysis and mapping of georeferenced, individual-level data can help identify important geographical patterns or lead to knowledge significant for dealing with specific social issues in a particular area. However, given the need to protect personal privacy when using geospatial data, the possibility for undertaking geographical analysis on certain types of individual-level data is becoming increasingly circumscribed. This article addresses the need to protect geoprivacy while making georeferenced, individual-level data available in such a way that analytical results are not significantly affected. The effectiveness of three geographical masks with different perturbation radii (r) is examined using a data set for lung-cancer deaths in Franklin County, Ohio, in 1999. The findings reveal a rather consistent trade-off between data confidentiality and accuracy of analytical results. There seems to be a threshold r-value at which the results of analyses on masked data become substantially different from the original results. An r that produces an area about the average size of the study-area census-block groups achieves a desirable optimum trade-off between privacy protection and accuracy of results. The study shows that implementing appropriate geographical masks may help data managers or researchers establish the desirable trade-off, in a particular context, between privacy protection and accuracy of geographic information.

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References

Armstrong, M.P. 2002. "Geographic Information Technologies and Their Potentially Erosive Effects on Personal Privacy." Studies in the Social Sciences 27/1: 19-28.Geographic Information Technologies and Their Potentially Erosive Effects on Personal Privacy. Studies in the Social Sciences 27:19-28

Armstrong, M.P., G. Rushton, and D.L. Zimmerman. 1999. "Geographically Masking Health Data to Preserve Confidentiality." Statistics in Medicine 18/5: 497-525.Geographically Masking Health Data to Preserve Confidentiality. Statistics in Medicine 18:497-525

Bailey, T.C., and A.C. Gatrell. 1995. Interactive Spatial Data Analysis. Essex, England: Longman.Interactive Spatial Data Analysis

Bethlehem, J.G., W.J. Keller, and J. Pannekoek. 1990. "Disclosure Control of Microdata." Journal of the American Statistical Association 85: 38-45.Disclosure Control of Microdata. Journal of the American Statistical Association 85:38-45

Brown, M.P. 2000. Closet Space: Geographies of Metaphor from the Body to the Globe. New York: Routledge.Closet Space: Geographies of Metaphor from the Body to the Globe

Clarke, K.C., S.L. McLafferty, and B.J. Tempalski. 1996. "On Epidemiology and Geographic Information Systems: A Review and Discussion of Future Directions." Emerging Infectious Diseases 2/2: 85-92.On Epidemiology and Geographic Information Systems: A Review and Discussion of Future Directions. Emerging Infectious Diseases 2:85-92

Cox, L. 1994. "Matrix Masking Methods for Disclosure Limitation in Microdata." Survey Methodology 20/2: 165-69.Matrix Masking Methods for Disclosure Limitation in Microdata. Survey Methodology 20:165-69

Cox, L. 1996. "Protecting Confidentiality in Small Population Health and Environmental Statistics." Statistics in Medicine 15: 1895-905.Protecting Confidentiality in Small Population Health and Environmental Statistics. Statistics in Medicine 15:1895-905

Cromley, E.K., and S.L. McLafferty 2002. GIS and Public Health. New York: Guilford.GIS and Public Health

Cromley, E.K., R.G. Cromley, and Y. Ye. 2004. "Online Reporting and Mapping of Spatially Aggregated Individual Records Selected by User Queries." Cartographica 39/2: 5-13.Online Reporting and Mapping of Spatially Aggregated Individual Records Selected by User Queries. Cartographica 39:5-13

Curry, M.R. 1997. "The Digital Individual and the Private Realm." Annals of the Association of American Geographers 87/4: 681-99.The Digital Individual and the Private Realm. Annals of the Association of American Geographers 87:681-99

Curry, M.R. 1998. Digital Places: Living with Geographic Information Technologies. New York: Routledge.Digital Places: Living with Geographic Information Technologies

Dobson, J. 1998. "Is GIS a Privacy Threat?" GIS World 11/7:20-21. Available at http://www.geoplace.com/gw/1998/0798/798onln.aspIs GIS a Privacy Threat?. GIS World 11:20-21

Duncan, G.T., and R.W. Pearson. 1991. "Enhancing Access to Microdata While Protecting Confidentiality: Prospects for the Future." Statistical Science 6/3: 219-32.Enhancing Access to Microdata While Protecting Confidentiality: Prospects for the Future. Statistical Science 6:219-32

Elliott, P., J.C. Wakefield, N.G. Best, and D.J. Briggs. 2000. Spatial Epidemiology: Methods and Applications. Oxford: Oxford University Press.Spatial Epidemiology: Methods and Applications

Felligi, I.P. 1972. "On the Question of Statistical Confidentiality." Journal of the American Statistical Association 67: 7-18.On the Question of Statistical Confidentiality. Journal of the American Statistical Association 67:7-18

Gatrell, A.C., and M. Loytonen. 1998. "GIS and Health Research: An Introduction." In GIS and Health, ed. A.C. Gatrell and M. Loytonen. London: Taylor and Francis. 3-16.GIS and Health Research: An Introduction 3-16

Gatrell, A.C., T.C. Bailey, P.J. Diggle, and B.S. Rowlingson. 1996. "Spatial Point Pattern Analysis and its Application in Geographical Epidemiology." Transactions of the Institute of British Geographers n.s. 21: 256-74.Spatial Point Pattern Analysis and its Application in Geographical Epidemiology. Transactions of the Institute of British Geographers 21:256-74

Goss, J. 1995. "We Know Who You Are and We Know Where You Live: The Instrumental Rationality of Geodemographics Systems." Economic Geography 71: 171-98.We Know Who You Are and We Know Where You Live: The Instrumental Rationality of Geodemographics Systems. Economic Geography 71:171-98

Gordis, L., and E. Gold. 1980. "Privacy, Confidentiality, and the Use of Medical Records in Research." Science 207: 153-56.Privacy, Confidentiality, and the Use of Medical Records in Research. Science 207:153-56

Järup, L. 2000. "The Role of Geographical Studies in Risk Assessment." In Spatial Epidemiology: Methods and Applications, ed. P. Elliot, J.C. Wakefield, N.G. Best, and D.J. Briggs. Oxford: Oxford University Press. 415-33.The Role of Geographical Studies in Risk Assessment 415-33

Kwan, M.-P. 1998. "Space—Time and Integral Measures of Individual Accessibility: A Comparative Analysis Using a Point-Based Framework." Geographical Analysis 30/3: 191-216.Space—Time and Integral Measures of Individual Accessibility: A Comparative Analysis Using a Point-Based Framework. Geographical Analysis 30:191-216

Kwan, M.-P. 2000. "Analysis of Human Spatial Behavior in a GIS Environment: Recent Developments and Future Prospects." Journal of Geographical Systems 2/1: 85-90.Analysis of Human Spatial Behavior in a GIS Environment: Recent Developments and Future Prospects. Journal of Geographical Systems 2:85-90

Ohio Department of Health. 2001. 1999 Ohio Mortality Public Use Statistical File: Description and File Documentation. Columbus, OH: Center for Public Health Data and Statistics, Ohio Department of Health.1999 Ohio Mortality Public Use Statistical File: Description and File Documentation

Onsrud, H., J.P. Johnson, and X. Lopez. 1994. "Protecting Personal Privacy in Using Geographic Information Systems." Photogrammetric Engineering and Remote Sensing 60/9: 1083-95.Protecting Personal Privacy in Using Geographic Information Systems. Photogrammetric Engineering and Remote Sensing 60:1083-95

Public Health Service Act. 1999. 42 U.S.C. 201.

Google Scholar

Rowlingson, B.S., and P.J. Diggle. 1993. "SPLANCS: Spatial Point Pattern Analysis Code in S-Plus." Computers and Geosciences 19/5: 627-55.SPLANCS: Spatial Point Pattern Analysis Code in S-Plus. Computers and Geosciences 19:627-55

Silverman, B.W. 1986. Density Estimation for Statistics and Data Analysis. London: Chapman and Hall.Density Estimation for Statistics and Data Analysis

Snow, J. 1855. On the Mode of Communication of Cholera. London: Churchill Livingstone.On the Mode of Communication of Cholera

URISA. 2003. A GIS Code of Ethics. Park Ridge, IL: Urban and Regional Information Systems Association. Available at http://www.urisa.org/ethics/code_of_ethics.htm

Google Scholar

Information & Authors

Information

Published In

Cartographica: The International Journal for Geographic Information and Geovisualization

Volume 39 • Number 2 • June 2004

Pages: 15 - 28

History

Published in print: June 2004

Published online: 19 September 2006

Keywords

Authors

Affiliations

Mei-Po Kwan

Department of Geography, The Ohio State University, Columbus, OH, USA

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Irene Casas

Department of Geography, University at Buffalo-SUNY, Buffalo, NY, USA

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Ben Schmitz

Environmental Systems Research Institute, Inc., Danvers, MA, USA

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