Task

Uncertainty is an unavoidable property of the world, information about the world, and our cognition of the world. Your first task is to examine what is meant by uncertainty, data quality and error.

Elements of Data Quality
[ pdf ]

Source: Trodd N, 2003. Elements of data quality.
e-Tutorials Complete the continuous self-assessed exercises in Elements of Data Quality
Spatial Accuracy of Environmental Hazards Databases Source: Scott et al., 1997. Spatial accuracy of the EPA's Environmental Hazards Databases and their use in environmental equity analyses, Applied Geographic Studies, 1, 45-61.
Uncertainty in the Conception of Geographic Phenomena
[ pdf ]

Source: Longley PA, Goodchild MF, Maguire DJ and Rhind DW, 2001. Introduction and Uncertainty in the conception of geographic phenomena, Ch 6 sections 6.1 and 6.2 in Geographic Information Systems and Science. New York: Wiley. pp. 124-130.

Updated source: Longley PA, Goodchild MF, Maguire DJ and Rhind DW, 2005. Ch 6 sections 6.1 and 6.2 in Geographic Information Systems and Science. New York: Wiley. pp. 128-136.

Spatial Reasoning and Uncertainty Source: Worboys M and Duckham M, 2004. Spatial reasoning and uncertainty, Ch 9 in GIS: a computing perspective, Boca Raton, Fl: CRC Press.
Uncertainty, Knowledge Discovery and Data Mining in GIS
[ pdf ]
Source: Foody G, 2003. Uncertainty, knowledge discovery and data mining in GIS, Progress in Physical Geography, 27, 113121.
Task Your task is to characterise sources of error and consider the spatial pattern of uncertainty in a data set. I am sure you will not be surprised to learn that error in GIS is not randomly distributed and that, for example, boundaries act as 'error-magnets'.
Uncertainty in the Measurement and Representation of Geographic Phenomena
[ pdf ]

Source: Longley PA, Goodchild MF, Maguire DJ and Rhind DW, 2001. Introduction and Uncertainty in the measurement and representation of geographic phenomena, Ch 6 section 6.3 in Geographic Information Systems & Science. New York: Wiley. pp. 130-137.

Updated source: Longley PA, Goodchild MF, Maguire DJ and Rhind DW, 2005. Ch 6 section 6.3 in Geographic Information Systems and Science. New York: Wiley. pp. 136-144.

Error Sources and Propagation
[ pdf ]
Source: Trodd N, 2003. Error sources and propagation.
e-Tutorials Complete the continuous self-assessed exercises in Error Sources and Propagation
Boundary Uncertainty Source: De Groeve T and Lowell K, 2001. Boundary uncertainty assessment from a single forest-type map, Photogrammetric Engineering and Remote Sensing, 67, 717-726.
Uncertainty in Photointerpreted Boundaries Source: Edwards G and Lowell KE, 1996. Modelling uncertainty in photointerpreted boundaries, Photogrammetric Engineering and Remote Sensing, 62, 337-391.
Task Describing error in one data set allows us to consider how errors might accumulate through spatial analysis. We can track cumulative uncertainty through the data stream and into the information chain. Furthermore, the end-user is also concerned with how error is amplified through data processing. Your task is to assess how error propagates in calculating measurements and metrics, univariate and multivariate spatial operations.
Uncertainty in the Analysis of Geographic Phenomena
[ pdf ]

Source: Longley PA, Goodchild MF, Maguire DJ and Rhind DW, 2001. Uncertainty in the analysis of geographic phenomena, Ch 6 section 6.4 in Geographic Information Systems and Science. New York: Wiley. pp. 137-139.

Updated source: Longley PA, Goodchild MF, Maguire DJ and Rhind DW, 2005. Ch 6 section 6.4 in Geographic Information Systems & Science. New York: Wiley. pp. 144-152.

Modelling Error Propagation in Dynamic Models
[ pdf ]
Source: Karssenberg D and De Jong K, 2005. Dynamic environmental modelling in GIS: 2. Modelling error propagation, International Journal of Geographical Information Science, 19, 623 - 637.
A General Framework for Error Analysis Source: Leung Y, Ma J-H and Goodchild MF, 2004. A general framework for error analysis in measurement -based GIS, Journal of Geographical Systems, 6 (4), Special Issue.
Area Calculations
[ URL ]
Source: Goodchild MF, Shortridge AM and Fohl P, 1998. Encapsulating simulation models with geodata, NCGIA. <http://www.ncgia.ucsb.edu/~ashton/demos/propagate.html> URL last accessed 16-01-2007.
Landscape Metrics Source: Arnot C, Fisher PF, Wadsworth R and Wellens J, 2004. Landscape metrics with ecotones: pattern under uncertainty, Landscape Ecology, 19, 181-195.
Overlay Analysis: Vector
[ ScienceDirect ] [ pdf ]
Source: Shi W, Cheung C-K and Tong X, 2004. Modelling error propagation in vector-based overlay analysis, ISPRS Journal of Photogrammetry and Remote Sensing, 59, 47 59.
Overlay Analysis: Raster Source: Veregin H, 1995. Developing and testing of an error propagation model for GIS overlay operations, International Journal of GIS, 9, 595-619.
Overlay Analysis: Raster Source: Arbia G, Griffiths D and Haining R, 1998. Error propagation modelling in raster GIS: overlay operations, International Journal of GIS, 12, 145-167.
Overlay: Problems in Planning Source: Bailey RG, 1988. Problems with using overlay mapping for planning and their implications for geographic information systems, Environmental Management, 12, 1-17.
Viewshed Source: Fisher P, 1992. First experiments in viewshed uncertainty: simulated fuzzy viewsheds, Photogrammetric Engineering and Remote Sensing, 58, 345-352.
Task The following case studies exemplify the problem of uncertainty in different situations. Your task is to identify the nature of the uncertainty in each case study. Which case studies find it difficult to be objective? Which consider error propagation? How many seek to quantify positional error?
Siting Power in Southern West Virginia
[ ScienceDirect ] [ pdf ]
Source: Towers G, 1997. GIS versus the community. Siting power in southern West Virginia, Applied Geography, 17, 111-125.
Siting a Nuclear Waste Disposal Facility
[ pdf ]
Source: Evans A, Kingston R and Carver S, 2004. Democratic input into the nuclear waste disposal problem: the influence of geographical data on decision making examined through a web-based GIS, Journal of Geographical Systems, 6, 117-132.
Siting Public Services
[ ScienceDirect ] [ pdf ]
Source: Murray AT, 2003. Site placement uncertainty in location analysis, Computers, Environment and Urban Systems, 27, 205221.
Deriving Leaf Area Index and Surface Roughness Parameters for Land-Surface Models Source: DeFries R and Los SO, 1999. Implications of land cover misclassification for parameter estimates in global land-surface models: an example from the simple biosphere model (SiB2), Photogrammetric Engineering and Remote Sensing, 65, 1083-1088.