In a {{tree} the branching factor of a node refers to the number of branches/children of the node. For the tree as a whole this may be fixed (e.g. a branching factor of 2 for a binary tree) or may vary between nodes (as is often the case in search trees). One may therefore talk about a maximum or average branching factor of a tree. For example, for the first move in Go there are 19x19 possible moves, so the branching factor at the root is 361 (although some are equivalent).
. In a directed graph , that is when the links/arcs between nodes have a direction, one can talk about the forward and backward branching factors. The former is the number of outward links and the latter the numer of inward links.
Defined on page 58
Used on Chap. 4: pages 58, 60, 61, 68, 80; Chap. 11: page 222; Chap. 15: page 347
Also known as backward branching factor, backward, forward, forward branching factor