Bayesian network represented as a directed acyclic graph.
Rectangular box nodes represent the 72-hr LC50 data for each group of species (in each box there will be at least one individual species measurements). Round nodes represent random variables: the subscript μ values denote the mean log10 72-hr LC50 for each group; σ2 is a measure of within-group interspecies variance; µhyper and τ2hyper are the mean and variance of the hyper-population of group means. Directed arrows represent conditional probability statements. Prior distributions are placed over σ2, µhyper and τ2hyper.