New Zealand Statistical Association
2004 Conference
Submitted Talks
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Murray Jorgensen
University of Waikato

Estimating a Density of Microbial Densities

I review the method of "Most Probable Number" for estimating the number of micro-organisms in a physical sample using a dilution assay and show how the problem may be formulated in Generalized Linear Model terms.

Then I look at the harder problem of estimating the parameters of a log-normal distribution of microbial densities in a region given the results of dilution assays at a random sample of sites in the region. My approach uses a Monte Carlo EM algorithm.