 Figure 5: An ECHO network for hypotheses P1 and P2 and evidence units Q1 and Q2. Solid lines represent excitatory links, the dotted line an inhibitory link. Because Q1 and Q2 are evidence nodes, they take a constant excitatory value of 1 from E. Started from values of .01 and following Thagard’s updating, P1 dominates P2 once the network has settled down: a hypothesis that explains more dominates its alternative. Adapted from Thagard 1992.