The Dictionary of Human Geography (77 page)

Read The Dictionary of Human Geography Online

Authors: Michael Watts

BOOK: The Dictionary of Human Geography
9.45Mb size Format: txt, pdf, ePub
geodemographics
Geodemographics is ?the analysis of people by where they live? (Sleight, (NEW PARAGRAPH) or, more precisely, by a data based classification of residential location (although classifications have also been produced for workplace, financial services and cyberspace). The origins of geodemographics include Charles Booth?s poverty Maps of London (1898 9; see http://booth.lse.ac.uk) and the 1920s 1930s chicago schooL of urban soci ology. During the twentieth century, the increasing availability of national census data and the development of computation permit ted multivariate summaries of census zones to be produced, and for those areas to be grouped together on a like with like basis using cluster ing techniques (see cLassification and regionaLization). (NEW PARAGRAPH) Those methodological developments pro vided the foundation for modern geodemo graphics a major industry used by corporate, governmental, non profit and political groups to deliver key advertising and services to their audiences, customers and users (Weiss, 2000). Commercial applications emerged during the late 1970s with the launch of PRIZM, by Claritas, in the USA and ACORN, by CACI, in the UK. Today?s classifications include not only census data, but also shopping, electoral, financial and other data about the ?objects? to be classified (commonly individuals, house holds, postcodes, Zip codes, census tracts or electoral wards). ACORN currently categor izes 1.9 million UK postcodes into one of five, seventeen or fifty six types (plus some ?unclas sified?), using over 125 demographic statistics and 287 lifestyle variables. PRIZM NE incorp orates both househoLd and census data to describe, for example, Beverley Hills 90210 as containing ?Blue Blood Estates?, ?Bohemian Mix? and ?Money & Brains? (amongst other segments). There are geodemographic classifi cations of most of Western Europe, Northern America, Brazil, Peru, Australasia, South (NEW PARAGRAPH) Africa, parts of Asia and some of China, includ ing Hong Kong. (NEW PARAGRAPH) Many geographers have been active in developing geodemographic classifications, in cluding Super Profiles (Charlton, Openshaw and Wymer, 1985), GB Profiles and a freely downloadable classification of UK Census Output Areas (at http://neighbourhood.statis tics.gov.uk). Others have been more critical. One concern is that for some applications the cluster groups are not sufficiently homoge neous for them to represent well the individ uals (or households) allocated to them. Voas and Williamson (2001) suggest that apparent differences between geodemographic classes conceal a much greater diversity within the classes. A related concern is that the montage of variables forming a geodemographic classi fication creates something of a black box, making it hard to determine the key predictors of the geographical phenomena being ana lysed. Care needs to be taken when interpret ing geodemographic outputs because they are usually indexed as rates in one cluster, relative to all others. To find that an event is of above average prevalence in one geodemographic group is no guarantee that it is common there: the result could apply to a small minor ity of the population but still a larger propor tion than for other clusters. (NEW PARAGRAPH) Surrounding geodemographics are broader debates in human geography, including those about representation, quantitative method ologies, empiricism, generalization, induc tion versus deduction, data versus theory led approaches to understanding, neo LiberaL economies and the politics and commercial ization of data collection, privacy and social discrimination. Critical theorists have cited geodemographics as an example of ?software sorting', suggesting that the sorts of labelling used in geodemographic systems can produce stigmatization of certain places and potentially deny them the same level of (e.g. banking or insurance) service given to other neighbour hoods (Burrow, Ellison and Woods, 2005). However, the argument cuts two ways: geode mographics can also identify areas of social or material need, offering opportunity to better target the resources available to those places. (NEW PARAGRAPH) Geodemographic classifications can be used to interpolate market research and other sur vey data to standard administrative or ad hoc geographies allowing, as examples, estimation of: the levels of consumption of grocery prod ucts by supermarket catchment; demand for particular makes of car by dealership territory; or likely levels of diabetes by GP surgery catchment area. Whereas much academic de bate centres on the accuracy (or otherwise) of geodemographics for predicting the behaviour of individuals, in practice many users are inter ested in aggregate behaviour What, on aver age, is the most likely event, characteristic or behaviour at an area level, and how does this differ from other areas? (NEW PARAGRAPH) Increasingly, uses of geodemographics bring together academic, public policy and private sector stakeholders, applying geographical thinking to tackle questions of social concern. Geodemographics has stimulated a renais sance in applied geographical research, being recently used for investigating the spatial dis tributions of family names, predicting spatial variation in pupils' school examination per formances, examining inequalities in hospital admissions and for guiding local poLicing (all atwww.spatialliteracy.org). rh (NEW PARAGRAPH) Suggested reading (NEW PARAGRAPH) Charlton, Openshaw and Wymer (1985); Harris, Sleight and Webber (2005). (NEW PARAGRAPH)
Geographic Information Science (GISc)
In (NEW PARAGRAPH) the simplest sense, Geographic Information Science (GISc, or GIScience) is the theory that underlies geographic information sys tems (gis). The latter are the collection of hardware, software, output devices and prac tices are that used to analyse and map spatial entities and their relationships. GIS software might be used to determine the boundaries that distinguish areas with different average income levels in a city or a map of optimal delivery routes for a courier company. These results are, however, not transparent; the pro cess through which they are derived are known as black box. Geographic Information Science or the theoretical basis for GIS is concerned with how results are obtained in GIS and what questions can legitimately be asked. (NEW PARAGRAPH) GIScience explores how spatial objects be come digital entities, what effect that trans formation has on their digital ontoLogy, how different epistemoLogies affect onto logical repesentation, how to model relation ships between spatial entities, and how to visualize them so that human beings can inter pret the results (Raper, 1999). This pursuit draws on and extends developments in data modelling, computer science, cognition, visu aLization and a myriad fields that have emerged in response to information systems. (NEW PARAGRAPH) For the first several decades of GIS use, little attention was given to the differentiation between geographical information systems and science. By the beginning of the 1990s, however, there was a sense among academic researchers that GIS had forged new intellec tual territory. The term ?GIScience? was first used in a keynote speech given by Michael Goodchild during the July, 1990 Spatial Data Handling conference in Zurich. Goodchild noted that the GIS community is driven by intellectual curiosity about the representa tional and analytical capacity of Geographic Information Systems. He argued that GIS researchers should focus on fundamental pre cepts that underlie the technology rather than the application of existing technology. Fur thermore, he argued that there are unique characteristics of spatial data, and problems associated with their analysis, that differentiate GIS from other information systems. These properties include: the need to develop con ceptual moDELs of space; the sphericity of spa tial data (based on the shape of the Earth); problems with spatial data capture; spatial data uncertainty and error propagation; as well as algorithms and spatial data display. Given the distinctiveness of geographical data analysis and a growing community of researchers dedicated to solving technical and theoretical problems associated with GIS, Goodchild argued that ?GIS as a field con tain[s] a legitimate set of scientific questions?. Goodchild?s keynote address was followed by a summary article in the International Journal of GIS (IJGIS) in 1992. This oft cited article (Abler, 1993b; Dobson, 1993), was a beach head for the very successful effort to change the meaning of the ?S? word in GIS (Good child, 1992). (NEW PARAGRAPH) The GIScience acronym subsequently gar nered widespread support in most parts of the discipline. The name shift is manifest in other areas of geography. Progress in Physical Geog raphy routinely presents updates on GIScience rather than GISystems (Atkinson, 1997). The flagship journal IJGIS was renamed Inter national Journal of Geographical Information Science in January 1997; its editor, Peter Fisher, stressed that IJGIS had, in ten years of publication, predominantly reflected the development of theoretical bases that under pin subsequent systems: the science on which subsequent systems are based. Fisher turned to the (shorter) Oxford English Dictionary to support this distinction, noting that systems are a collection of related objects or an assem blage while science is defined as knowledge obtain through investigation. He noted that the International Geographical Union (IGU) had developed a working group for Geograph ical Information Science in 1996, the implica tion being that there is broad institutional support for this designation (Fisher, 1997). Marc Armstrong, the former North American editor of IJGIS, recalls that identifying aspects of GIS as science was an acknowledgement that many GIS researchers were neither using nor developing ?systems?, but were doing basic theoretical work that involved the ?system atization? of knowledge (Armstrong, pers. comm.). Despite a call for recognition of the scientific value of GIS, on the part of the aca demic community, the technology is indisput ably social in its construction, especially at the software level. (NEW PARAGRAPH) Questions about the underlying assump tions written into the code that comprises GISystems are the basis of GIScience. GIS cientists might legitimately question, for example, the premises of embedded algorith mic models. A hydrological model, for in stance, might be outdated and fail to reflect current understanding of flow processes. Queries about the assumptions of the model creators, their efficacy in multiple environ ments, and whether they are designed for use with vector (polygon) or raster (gridded) data all fall in the realm of GIScience. These types of questions strike at the efficiency and legitimacy of current Geographic Information Systems aLgorithms; their resolution is the basis for increase in the reliability of GIS for the average user. Such questions do not repre sent the entirety of GIScience, however. (NEW PARAGRAPH) Every stage of GISystems, from spatial data collection and input, to storage, analysis and, finally, output of maps, is based on the trans lation of spatial phenomena into digital terms. At each step of GIS, data are manipulated for use in a digital environment, and these, often subtle, changes have profound effects on the results of analysis. Each of these transform ations involves a subtle shift in the representa tion of spatial entities, and accounting for these modifications and their implications is an important part of GIScience. Physical and social information about the world, once in digital form, is often manipulated and ana lysed in order to correspond to the researcher?s interpretation of the world. Thus it is of fundamental importance that GIScience de velop methods to monitor and account for the effects that possible transformations have on final representation. Finally, GIScience researchers are charged with developing methods of presenting analysis results such that their visual display is consistent with database results. (NEW PARAGRAPH) GIScience is concerned theoretically with every stage of digital representation. Spatial phenomena must be delineated and classified in preparation for input to data tables. dassi fication systems, however, must be compat ible with data tables, and this acts as a constraint to the development of categories. Many spatial phenomena manifest multiple characteristics, but not all of them can be in cluded in a database or the data would be infinite. The manipulation of data depends on the attributes that are recorded, or the objects that are defined. Different community boundaries, for instance, will render different results in an assessment of population health. Visualizing GIS results is likewise vulnerable to the vagaries of the digital environment, and must be consistent with human capacity for perception. At a small scaLe (larger area), for instance, only a limited number of attributes can be displayed or the map becomes over crowded. At a larger scale (smaller area), a greater number of attributes can be accommo dated. Each of these issues has a bearing on how spatial data are analysed and interpreted. (NEW PARAGRAPH) The GIScience research purview is the rep resentation of spatial data and their relation ships and these are ultimately expressed in terms of bits and bytes. Working in a digital environment is akin to speaking another lan guage that uses fundamentally different build ing blocks. If we think of the English language as being composed of twenty six letters that can be combined in various ways to form words, sentences and ideas, then GIS is based on two letters or digits zeros and ones that can be combined and manipulated to represent and analyse geographical phe nomena and relationships. But the environ ment and rules associated with manipulating geographical objects are quite different from those we are accustomed to using for conven tional text and graphics. The digital environ ment is constrained by digital parameters and the extent of representation possible through combinations and permutations of bits and bytes. (NEW PARAGRAPH) GIScience is not limited, however, to process oriented issues. It is engaged with how people represent their geographical envir onment, and who has the authority to repre sent space. Public Participation GIS (PPGIS) studies and engages with non profit groups and non governmental organizations that use GIS to represent themselves, and advocate for change (Elwood and Leitner, 2003). Other GIScientists address questions about femin ism and GIS, and whether the technology is inherently gendered (Kwan, 2002). Stacey Warren (2004) explains that PPGIS and feminism and GIS allow us to move the focus from analysis and representation in GIS to one that views the technology as a ?collaborative process that involves both people and machin ery?. This emphasis on social interactions be tween users, affected populations, and technology is evident in the growing number of Critical GIS scholars who have merged emancipatory agendas and theory from human geography with GIScience. (NEW PARAGRAPH) Developers and researchers postulate that GIScience transcends mere information systems and allows users to ask questions about spatial relations that were previously impossible to pose. Its champions argue that Geographic Information Science extends spa tial analysis by virtue of enhanced processing power that allows data intensive analyses to extend their geographical breadth. They claim that GIScience is a means of investigat ing previously obscured spatial relationships and contingencies. There is a tension between GIS scholars who view the technology as an emergent phenomenon, capable of initiating a shift in scientific methodology and other geographers who view it simply as a vehicle for concepts that emerge from geography. It is, of course, both. ns (NEW PARAGRAPH) Suggested reading (NEW PARAGRAPH) Longley, Goodchild, Maguire and Rhind (1999); Schuurman (2004). (NEW PARAGRAPH)

Other books

Out of Africa by Isak Dinesen
Chaos by Megan Derr
The Quaker Café by Remmes, Brenda Bevan
The Vacant Chair by Kaylea Cross
HH02 - A Reclusive Heart by R.L. Mathewson
Catching Lucas Riley by Lauren Winder Farnsworth
Always Unique by Nikki Turner