We assume a parallel, distributed protocol. If loopy prop. Single loop, discrete nodes. If a FP exists and all nodes are binary, the mode will be exact but the posteriors will be overly confident.
Faster convergence implies smaller error.
Arbitrary topology, Gaussian nodes. If a FP exists, the means will be exact, but the variances may be wrong. Faster convergence implies smaller error. Sufficient conditions for a FP to exist. Turbocode topology, binary nodes.