# 3.2. Statistical distribution of virus data

The major additional point specifically
relevant to honey bee virus research (and probably other pathogens) is that
virus titres follow an Exponential (~Logarithmic) distribution, rather than a
Normal distribution (Fig. 2; Gauthier *et
al.,* 2007; Brunetto *et al.,* 2009;
Yañez *et al.,* 2012; Locke *et al.,* 2012). Also, the prevalence of
very rare viruses (pathogens, parasites) may follow a Poisson distribution
rather than a Binomial distribution. These differences in how the primary virus
data is statistically distributed affects the design of an experiment, the
determination of sample sizes (Wolfe and Carlin, 1999), surveying strategy, the
analysis of pooled samples and the management of the data produced. This
subject is treated in more detail in the *BEEBOOK*
paper on statistical methods (Pirk *et al.,*
2013).