Local Moran
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Indications/Recommendations for use: Can be used to investigate local spatial clusters and as a diagnostic for outliers with respect to the measure of global association (local instability).
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Description: The Local Moran value for each observation gives an indication of the extent of significant spatial clustering of similar values around that observation.
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Test statistic: The Local Moran area statistics decompose Moran's I into contributions for each location. These local statistics are used to identify regions that differ significantly from those expected under the null hypothesis.
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Null Hypothesis:
There is no association between the value observed at a location and the values observed at nearby sites.
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Ho:
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Alternative Hypothesis:
When values, such as disease rates, cluster, nearby sites are similar
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Ha:
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GeoMed Inputs:
Region-specific disease frequency, spatial contiguity matrix (can be generated from ArcView boundary file)
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GeoMed Outputs:
Tabled information for outliers based on the distribution of the observed local statistic or the distribution of values generated from Monte Carlo simulations; choropleth map for disease frequency and Local Moran values
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Example Analysis
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Reference:
Anselin, L. Local indicators of spatial association-LISA, 1995. Geographical Analysis, 27:93-115.
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