Supplement 1. Maple file for constructing conditional probability tables from signed directed graphs, SDG graphical editor program, example BBNs for the parasitoid and lake mesocosm studies, and instruction guide for SDG-BBN construction.

File List Guide.pdf -- Instruction guide for SDG-BBN construction CPT Builder.mws -- Maple file that constructs conditional probability tables SDG Graphical Editor -- InstallAnywhere Self Extractor application that allows user to draw SDG and construct the transposed signed adjacency matrix °A parasitoid.neta -- Bayes net for parasitoid example lake.neta -- Bayes net for mesocosms example Description This instruction guide Guide.pdf describes in detail the transition from a signed directed graph (SDG) to a Bayesian Belief Network (BBN). The instruction guide begins by deriving the qualitative mathematics for the host-parasitoid example. Instructions are given for drawing an SDG and the associated matrix ºA using the SDG Graphical Editor. The guide shows how to construct the conditional probabilities using the Maple file CPT Builder.mws. Example Bayes nets are included for the parasitoid example (parasitoid.neta) and the lake mesocosms example (lake.neta). These latter two files use the BBN software Netica, available at www.norsys.com.