Abstract:

To describe the transformational characterization of Markov equivalence for directed maximal ancestral graphs, the authors proposed a sequence of transformation of bidirected edges to directed edges which preserve Markov equivalence. Therefore, any two equivalent directed maximal ancestral graphs can equivalently transform to each other via changing bidirected edges to directed edges, changing directed edges to bidirected edges and reversing directed edges.

Key words: ancestral graph, Markov equivalence, minimal collider path, covered edge