昆虫学百分率差异显著性统计分析的简易计算方法

A method of statistical tests of differences between percentages in entomological researches

昆虫学定量分析资料常有2类不同性质的百分率,即组成的百分率和独立的百分率。在进行差异显著性检验时,如果样本数n较大,则组成百分率可用标准正态变量μ检验。作者给出一个简便的计算公式:μ=n0.5|P1-P2|,其中ni,nj分别为第i,j组的频次数。如果只有2组,则μ=n0.5|P1-P2|,其中P1,P2分别为第1,2组的频次数。对独立的百分率进行F检验时,如果多数数据在30%～70%之外,则应通过反正弦变换使百分率变换为角度。这种变换的实际效果往往使差异显著性提高。

There are two different kinds of percentages in entomological research which are proportions and independent percentages. For statistical test of a difference between two constituent ratios, if the number of samples is large enough, one can use the standard normal distribution variable ,μ test. The authors gave a simple formula： μ=｜ni-nj｜/（ni＋nj）^0.5 , where ni, nj denote frequencies of groups i and j, respectively. If groups are only two, thenthe formula becomes even simpler： μ=n^0.5｜P1-P2｜ , where Pl and P2 are ratios of the two groups, respectively. For F test of a difference between independent percentages, if most data are smaller than 30% or greater than 70 %, a percentage, P should be transferred to an angle, α ： α = sin^-1 （ P）. In fact, this transfer results generally in a more significantly difference.