HETEROGENEITY OF ATTRIBUTE SAMPLING ERROR IN SPATIAL DATA SETS

This paper considers the standard error of the estimate of the mean of a spatially correlated variable in the case where data are obtained b y a process of random sampling. Two distinct mean estimation problems are identified: estimating the area mean and estimating the population mean. Methods are described for obtaining standard error estimates in the two cases and, within the limits of publicly available informatio n, the methods are implemented on average household income data at the census tract scale for Syracuse, New York. The purpose of the paper i s to draw attention to issues of data precision in relation to sampled geographic information on averages and in particular to consider the problems of estimating standard errors using such data. The paper also examines the extent to which standard errors vary between census trac ts.