47:
82:, making an enumeration unit that is relevant for one person meaningless to another. For example, a map that aggregates people by school districts will be more meaningful when studying a population of students than the general population. Traditional spatial analysis, by necessity, treats each discrete areal unit as a self-contained neighborhood and does not consider the daily activity of crossing the boundaries.
39:(MAUP), and like the MAUP, arises from how we divide the land into areal units. It is caused by the difficulty, or impossibility, of understanding how phenomena under investigation (such as people within a census tract) in different enumeration units interact between enumeration units, and outside of a study area over time. It is particularly important to consider the UGCoP within the discipline of
113:, along with technologies that can monitor the position of individuals in real time, are possible methods for addressing the UGCoP. These technologies allow scientists to analyze and visualize the 3D space-time path of people moving through a study area, and better understand their actual activity space.
117:
has also been employed to address the UGCoP by allowing researchers to better contextualize subjects' real and perceived activity space. These technologies have helped to address the problem by moving away from aggregate data and introducing a temporal component to the modeling of subject activity.
98:
All maps are wrong, and a cartographer must ensure that their maps' limitations are well documented to avoid misleading the users. With modern technology, there is an emphasis on individual-level data and understanding how individuals interact with their environment. When making maps with this
94:
states, "the phenomenon external to a geographic area of interest affects what goes on inside." As a study area is often a subset of the planet, data on the edges of the study area will be excluded. If the boundary demarcating the study area is permeable to travel, then the phenomena under
807:
Salvo, Deborah; Durand, Casey P.; Dooley, Erin E.; Johnson, Ashleigh M.; Oluyomi, Abiodun; Gabriel, Kelley P.; Van Dan Berg, Alexandra; Perez, Adriana; Kohl, Harold W. (June 2019). "Reducing the
Uncertain Geographic Context Problem in Physical Activity Research: The Houston TRAIN Study".
74:(MAUP) in that, it relates to aggregate units as they apply to individuals. The crux of the problem is that the boundaries we use for aggregation are arbitrary and may not represent the actual neighborhood of the individuals within them. While a particular enumeration unit, such as a
78:, contains a person's location, they may cross its boundaries to work, go to school, and shop in completely different areas. Thus, the geographic phenomena under investigation extends beyond the delineated boundary . Different individuals, or groups may have completely different
594:
Zhou, Xingang; Liu, Jianzheng; Gar On Yeh, Anthony; Yue, Yang; Li, Weifeng (2015). "The
Uncertain Geographic Context Problem in Identifying Activity Centers Using Mobile Phone Positioning Data and Point of Interest Data".
43:, where phenomena under investigation can move between spatial enumeration units during the study period. Examples of research that needs to consider the UGCoP include food access and human mobility.
99:
individual-level data, the UGCoP is one source of bias that can impact the results of an analysis. When these results inform policy, they can have real world ramifications.
438:
Chen, Xiang; Ye, Xinyue; Widener, Michael J.; Delmelle, Eric; Kwan, Mei-Po; Shannon, Jerry; Racine, Racine F.; Adams, Aaron; Liang, Lu; Peng, Jia (27 December 2022).
158:
880:"Developing a GIS-Based Online Survey Instrument to Elicit Perceived Neighborhood Geographies to Address the Uncertain Geographic Context Problem"
95:
investigation within it may extend beyond, and be impacted by, forces excluded from the analysis. This uncertainty contributes to the UGCoP.
544:"Contextual Uncertainties, Human Mobility, and Perceived Food Environment: The Uncertain Geographic Context Problem in Food Access Research"
716:"The Uncertain Geographic Context Problem in Identifying Activity Centers Using Mobile Phone Positioning Data and Point of Interest Data"
143:
665:"The Uncertain Geographic Context Problem in the Analysis of the Relationships between Obesity and the Built Environment in Guangzhou"
878:
Shmool, Jessie L.; Johnson, Isaac L.; Dodson, Zan M.; Keene, Robert; Gradeck, Robert; Beach, Scott R.; Clougherty, Jane E. (2018).
1088:
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International
Encyclopedia of Geography: People, the Earth, Environment and Technology: Uncertain Geographic Context Problem
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diagram of a space-time prism, and on the left is a map of the potential path area for two different time budgets.
1018:"Spatial Non-Stationarity Effects of Unhealthy Food Environments and Green Spaces for Type-2 Diabetes in Toronto"
110:
71:
36:
133:
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440:"A systematic review of the modifiable areal unit problem (MAUP) in community food environmental research"
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488:"Does the edge effect impact on the measure of spatial accessibility to healthcare providers?"
329:"How GIS can help address the uncertain geographic context problem in social science research"
168:
138:
924:
Tobler, Waldo (1999). "Linear pycnophylactic reallocation comment on a paper by D. Martin".
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193:
8:
223:
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951:
Franch-Pardo, Ivan; Napoletano, Brian M.; Rosete-Verges, Fernando; Billa, Lawal (2020).
778:
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Cartographica: The
International Journal for Geographic Information and Geovisualization
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Allen, Jeff (2019). "Using
Network Segments in the Visualization of Urban Isochrones".
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The UGCoP is particularly important when understanding food access and human mobility.
67:
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The UGCoP has further implications when considering the area outside of a study area.
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Zhou, Xingang; Liu, Jianzheng; Yeh, Anthony Gar On; Yue, Yang; Li, Weifeng (2015).
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Gao, Fei; Kihal, Wahida; Meur, Nolwenn Le; Souris, Marc; Deguen, Séverine (2017).
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The uncertain geographic context problem, or UGCoP, was first coined by Dr.
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when dealing with aggregate data. The UGCoP is very closely related to the
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International
Journal of Environmental Research and Public Health
275:
Kwan, Mei-Po (2012). "The
Uncertain Geographic Context Problem".
114:
722:. Advances in Geographic Information Science. pp. 107–119.
599:. Advances in Geographic Information Science. pp. 107–119.
953:"Spatial analysis and GIS in the study of COVID-19. A review"
218:
926:
International
Journal of Geographical Information Science
159:
Geographic information systems in geospatial intelligence
877:
806:
437:
663:
Zhao, Pengxiang; Kwan, Mei-Po; Zhou, Suhong (2018).
593:
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767:Annals of the Association of American Geographers
277:Annals of the Association of American Geographers
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810:Medicine & Science in Sports & Exercise
720:Advances in Spatial Data Handling and Analysis
597:Advances in Spatial Data Handling and Analysis
66:in 2012. The problem is highly related to the
54:using transit network data: On the right is a
1047:
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31:that can significantly impact the results of
852:. Geo Abstracts, University of East Anglia.
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1056:(3 ed.). University of Chicago Press.
492:International Journal of Health Geographics
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144:Concepts and Techniques in Modern Geography
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822:10.1249/01.mss.0000561808.49993.53
542:Chen, Xiang; Kwan, Mei-Po (2015).
404:The Modifiable Aerial Unit Problem
14:
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1052:Monmonier, Mark (10 April 2018).
846:An Introduction to Time-Geography
548:American Journal of Public Health
234:Tobler's second law of geography
204:Modifiable temporal unit problem
92:Tobler's second law of geography
977:10.1016/j.scitotenv.2020.140033
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385:10.1002/9781118786352.wbieg0599
229:Tobler's first law of geography
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111:Geographic information systems
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896:10.1080/00330124.2017.1416299
373:Matthews, Stephen A. (2017).
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72:Modifiable areal unit problem
37:Modifiable areal unit problem
1094:Problems in spatial analysis
345:10.1080/19475683.2012.727867
289:10.1080/00045608.2012.687349
134:Automotive navigation system
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884:The Professional Geographer
728:10.1007/978-3-319-19950-4_7
642:10.3138/cart.53.4.2018-0013
605:10.1007/978-3-319-19950-4_7
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50:Schematic and example of a
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457:10.1007/s44212-022-00021-1
16:Source of statistical bias
505:10.1186/s12942-017-0119-3
239:Traditional knowledge GIS
560:10.2105/AJPH.2015.302792
189:List of GIS data sources
129:Arbia's law of geography
938:10.1080/136588199241472
401:Openshaw, Stan (1983).
199:Map database management
164:GIS and aquatic science
843:Thrift, Nigel (1977).
761:Tobler, Waldo (2004).
682:10.3390/ijerph15020308
184:Integrated Geo Systems
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327:Kwan, Mei-Po (2012).
169:GIS and public health
139:Collaborative mapping
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1054:How to lie with maps
194:List of GIS software
969:2020ScTEn.739n0033F
224:Technical geography
106:Suggested solutions
70:, edge effect, and
1035:10.3390/su15031762
174:GIS in archaeology
68:ecological fallacy
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957:Sci Total Environ
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614:978-3-319-19949-8
444:Urban Informatics
214:Participatory GIS
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64:Mei-Po Kwan
1078:Categories
963:: 140033.
909:22 January
743:22 January
675:(2): 308.
251:References
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830:198375226
650:133986477
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358:4 January
56:schematic
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353:13215965
297:52024592
122:See also
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569:4539815
515:5725922
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25:UGCoP
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19:The
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