Journal article
Statistical Approaches to Monitoring
IN: Drinking Water Microbiology: Progress and Recent Developments. Springer-Verlag New York, Inc., New York. 1990. p 412-427, 1 fig, 1 tab, 48 ref
01 Apr 1990
Abstract
Little attention has been paid to the frequency distribution of microorganisms in the environment. Many studies which have been purported to study such distributions have failed to distinguish between real (i.e., environmental) distribution characteristics and those which might be contributed by analytical methods. There are a number of statistical techniques for isolating these analytical contributions. As a reference point for consideration of variability of an assay technique, the Poisson distribution is convenient; however, it is often found that the distribution of microorganisms in water samples does not follow the Poisson distribution. One possible mechanism which may account for non-Poisson distributions of counts among replicates is the existence of clumps of organisms. It is also possible that methods intrinsic to the analytical or sampling methodology may impose a non-Poisson distribution on replicated counts. Two of many examples of distributions for discrete variables which have greater than Poisson variability are the negative binomial and the Poisson with added zero's model. The effects of distribution of quantal assays and all-or none assays are discussed. Workers who investigate microbial density distribution should carefully consider the effect of analytical sampling errors both in their experimental design and in their data analysis techniques. (See also W91-06194) (VerNooy-PTT)
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Details
- Title
- Statistical Approaches to Monitoring
- Creators
- C HaasB Heller
- Publication Details
- IN: Drinking Water Microbiology: Progress and Recent Developments. Springer-Verlag New York, Inc., New York. 1990. p 412-427, 1 fig, 1 tab, 48 ref
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- Civil, Architectural, and Environmental Engineering
- Identifiers
- 991019189306304721