Quadrat Analysis_RW_Thomas

The test has been applied to the observed and poisson

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Unformatted text preview: nce level are listed in Table Table 1 and the results at the p 3. The test produces the same conclusion as Chi-square, that is the observed distribution is adequately described by the Poisson model. Fig.3: The relationship between Type I and Type II errors for the D statistic (iii) The Variance/mean ratio For an observed frequency array the variance/mean ratio is given by (34) values of m are considered in the evaluation of the test statistic, although a corresponding disadvantage is the loss of detail associated with the D statistic because only the maximum deviation contributes to the final value of D. Again the problem arises with the D statistic that the research worker is usually hoping to accept the null hypotheses, which makes the minimization of Type II errors of paramount importance in the selection of a significance level. Fig.3 summarises the results of some experimental work by Lindgren (1975) on the relationship between Type I and Type II errors for the D statistic when the sample size (n) is 10. It can be seen that the prob- The ratio defined by (34) is used in the construction o...
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