Junction Tree

Also known as a “join tree”.

A junction tree is the internal structure that Netica uses for belief updating.  Netica compiles a Bayes net or decision net into a junction tree for efficiency.

The junction tree T of triangulated net G is a tree with the cliques of G as nodes, such that for every node N of G, if we remove from T all cliques not containing N, the remaining subtree remains connected.  In other words, any two cliques containing N are either adjacent in T or connected by a path made entirely of cliques that contain N.

You can examine the junction tree that Netica creates for a Bayes net by making a text report using Report → Junction Tree after compiling.