The modifiable areal unit problem maup is a source of statistical bias. The modifiable areal unit problem maup raises issues when census. The modifiable areal unit problem maup springerlink. Aug 21, 2012 from the brief description of your study design i would imagine that the modifiable areal unit problem maup may also be a problem for you. Pdf the modifiable areal unit problem and implications for.
The modifiable areal unit problem in traffic safety. The issue was first recognized by gehlke and biehl in 1934 and later described in detail in a famous article by openshaw 1984 and in the book by arbia 1988. There has been a recent flurry of interest in dasymetric population mapping. The modifiable area unit problem maup, a term intr oduced by openshaw and ta ylors 1979 classic paper, has long been recognized as a potentially troublesome feature of aggr egated data, such as census data. Openshaw s, taylor pj 1979 a million or so correlation coefficients, three experiments on the modifiable areal unit problem. Price new from used from paperback, 1983 please retry. Even though gehlke and biehl 1934 discovered certain aspects of the modifiable areal unit problem maup, the term maup was not coined formally until openshaw and taylor 1979 evaluated. From the brief description of your study design i would imagine that the modifiable areal unit problem maup may also be a problem for you. Ndvi, scale invariance and the modifiable areal unit. Quarterly journal of economics and economic policy, institute of economic research, vol. Numerous and frequentlyupdated resource results are available from this search. In the modifiable areal unit problem maup literature, it is known that in measuring spillover effects, the magnitudes of spillovers are different depending on the scale of the temporalspatial. These lasted for 2 or 3 years until 1979 and from this came the edited book spatial representation and spatial interaction edited by masser and brown, 1979. Applies where data are aggregated to areal units which could take many forms e.
For example, if the display shows aggregated data, one must pay close attention to the aggregation unit when interpreting e. First, modifiable areal unit problem maup is one of the main analytical problems associated with the use of data aggregated to geographical areas gehlke and biehl,1934. Search for library items search for lists search for contacts search for a library. The inference is thus that the modifiable areal unit problem is unavoidable. Spatial autocorrelation of cancer incidence in saudi arabia authors. If there is considerable variation, that leads to the potential confounding problem known as the modifiable areal unit problem openshaw 1984, which should be addressed in the paper, because it can lead to statistical bias and misleading results. Martinus nijhoff, dordrecht and this really launched the whole business of the modifiable areal unit problem maup that was stans particular baby. Some other methodological issues that should be addressed. This seminal short book by one of the most well known authors on the topic. Concepts and techniques in modern geography catmog 38. The modifiable areal unit problem and implications for landscape ecology. A treatise on the geographical scale of agglomeration. Problems associated with arbitrary geographic units are known as the modifiable areal unit problem maup in the spatial analysis and quantitative geography literatures. Pdf the modifiable areal unit problem in regional economics.
The modifiable areal unit problem maup openshaw 1984 is a problem whereby conclusions may change if one aggregates the same underlying data to a new level of spatial aggregation. First, it reduces the effect of the modifiable areal unit problem maup. Some eoeica a aie asecs o saia ieacio soig moes sa oesaw s oesaw 5 a ioucio o e suace aaysis uwi 6. The modifiable areal unit problem concepts and techniques in. However, the ancillary coverages that underlie current dasymetric methods are. Exploring the modifiable areal unit problem in spatial. The maup is a problem arising from the imposition of artificial units of spatial reporting on continuous geographical phenomena, leading to artifacts or errors are created when one groups data into units for analysis. The maup can be observed through two effects, one caused by scaling and the other by zoning see section 2 for more details. The modifiable areal unit problem maup in physical. Health and environment information systems for exposure and.
In the literature, conclusions on the relationship between no 2 and health outcomes are divided, and this situation may in part be due to the selection of an. One of the difficulties, implicit in kendall and yule 1950 but explicit in openshaw 1984, is that many kinds of geographical data inevitably seem to require reporting in some areal units, and that these units are always to some extent arbitrary. The classic text on maup is the 1983 paper openshaw, stan. The modifiable areal unit problem and implications for landscape. The modifiable areal unit problem maup is an important phenomenon associated with the. Oclcs webjunction has pulled together information and resources to assist library staff as they consider how to handle coronavirus. It has been long recognized that there are issues related to the modifiable areal unit problem maup pertaining to indices such as ndvi and images at varying spatial resolutions. Wrigley n ed statistical applications in the spatial sciences. The modifiable areal unit problem maup is a source of statistical bias that is common in spatially aggregated data, or data grouped into regions or districts where only summary statistics are produced within each district, especially where the districts chosen are not suitable for the data.
However, formatting rules can vary widely between applications and fields of interest or study. An appendix to statistic of deadly quarrels, general systems. Second issue is, integration of aggregate census data with disaggregate land use data. Theory and practice, first published in 2003, provides a broad ranging treatment of the field of spatial data analysis. In an investigation of the parameter estimates from a multiple linear regression model and a multiple logit regression model, conclusions are drawn about the sensitivity of such estimates to variation in scale and zoning systems. Maup affects results when pointbased measures of spatial phenomena are aggregated into districts, for example, population density or illness rates. Agrawal 2007 areal interpolation of population counts using preclassified land cover data. The modifiable areal unit problem analysis of correlation and regression, equilibrium.
The modifiable areal unit problem concepts and techniques in modern geography paperback 1983. The modifiable areal unit problem analysis of correlation. The modifiable areal unit problem maup raises issues when census tracts are used as neighbourhood proxies, and no other alternate spatial structure is used for sensitivity analysis. The effect of granularity is also reflected in geostatistical prediction, which is classically known as the modifiable areal unit problem a geographic manifestation of ecological fallacy causing spurious conclusion due to spatial aggregation openshaw, 1984. This seminal short book by one of the most well known authors on the topic is a great place to start your reading. The modifiable areal unit problem concepts and techniques in modern geography paperback 1983 by stan openshaw author. Another less obvious, but serious issue, is the modifiable areal unit problem maup openshaw, 1983, which refers to the problem that the results of spatial data analysis may depend heavily on where the areal boundaries are laid and the scale at which data are aggregated. Ijerph free fulltext arealevel walkability and the. Oct 31, 2011 the modifiable areal unit problem maup raises issues when census tracts are used as neighbourhood proxies, and no other alternate spatial structure is used for sensitivity analysis. Modifiable areal unit problem gis wiki the gis encyclopedia. Health and environment information systems for exposure.
Chapter 5 more on thematic maps crime mapping in r. Yearbook of the society for the advancement of general systems theory, society for general systems research. Concepts of scale and scaling arizona state university. This, then, is the crux of the modifiable areal unit problem maup. At the same time, the conceptualization of place at the local scale is one of the weakest theoretical aspects in health geography. The modifiable areal unit problem maup is a serious analytical issue for. In an investigation of the parameter estimates from a multiple linear regression model and a multiple logit regression model, conclusions are drawn about the sensitivity of such estimates to.
Even though gehlke and biehl 1934 discovered certain aspects of the modifiable areal unit problem maup, the term maup was not coined formally until openshaw and taylor 1979 evaluated systematically the variability of correlation values when different boundaries systems were used in the analysis. Moreover, and without taking into account the aggregation method applied, there is an implicit risk that is known in the literature as modifiable areal unit problem maup openshaw, 1984. It begins with an overview of spatial data analysis and the importance of location place, context and space in scientific and policy related research. The modifiable areal unit problem in multivariate statistical. Many canadian population health studies, including those focusing on the relationship between exposure to air pollution and health, have operationalized neighbourhoods at the census tract scale. Almost all works about the maup reference openshaw. The maup occurs when analyzing data that are recorded or reported for arbitrary spatial units. Reliable information about the coronavirus covid19 is available from the world health organization current situation, international travel. Scale, aggregation, and the modifiable areal unit problem. Have you read openshaws 1984 and cressies 1996 papers. Openshaw 1984 maup correlation and dependence spatial. It refers to the fact that when point data is aggregated into areal units, the variation in how the units, or regions, are delineated can cause significant variation in the aggregated values at any point. The major research objective of the work is to examine the scale problem that constitutes one of the aspects of the modifiable areal unit problem.
The modifiable areal unit problem maup is a source of statistical bias that can significantly impact the results of statistical hypothesis tests. Changing the grain of data also sometimes causes quantitative bias in patterns through what has been termed the modifiable areal unit problem openshaw 1984. The modifiable areal unit problem is endemic to all spatially aggregated data. Geographic space as a living structure for predicting. The maup applies to two separate, but interrelated, problems with spatial data analysis. Use of gis and exposure modeling as tools in a study of cancer incidence in a population exposed to airborne dioxin. The examination of the modifiable areal unit problem is extended into multivariate statistical analysis. How do the modifiable areal unit problem and modifiable. Exploring the modifiable areal unit problem in spatial water. The modifiable areal unit problem maup is a long standing, unsolved problem in geography sciences. The modifiable areal unit problem maup in the relationship. In geography, scale effects have been studied for several decades in the context of the modifiable areal unit problem or maup openshaw 1984, jelinski and wu 1996, marceau 1999. Despite a substantial literature in the related field of geography on the potential influence of the maup, the urban economic modeling tradition has not paid much attention to this issue.
The criteria used to define the areal unit of analysis influences the results of spatial assessments e. James cheshire and oliver ubertis the information capital is full of beautiful and clever maps book site. Even though gehlke and biehl 1934 discovered certain aspects of the modifiable areal unit problem maup, the term maup was not coined formally until openshaw and taylor 1979 evaluated systematically the variability of correlation values when different. This problem is mostly called modifiable areal unit problem maup. Out of print, but available for free on the internet here. This problem is related with the high sensitivity of statistical and econometric results to different aggregations of geographical data, which can. The issue of maup occurs when the spatial zoning system used to collect or report geographical data is modifiable or arbitrary openshaw, 1984. This research addresses the question as to whether or not the normalised difference vegetation index ndvi is scale invariant i. The modifiable areal unit problem concepts and techniques. The paper focuses on the issue of the modifiable areal unit problem, which means a possibility of obtaining various results for spatial economic analyses depending on the assumed composition of territorial units. The scale effect relates to the size of the areal units that we use and the.
The modifiable areal unit problem maup refers to the sensitivity of statistical research results to the initial spatial nomenclature used. Despite a substantial literature in the related field of geography on the potential influence of the maup, the urban economic modeling. Cultural dasymetric population mapping with historical gis. Modifiable areal unit problem an overview sciencedirect.
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