Directionality is unlikely to exist in such a graph. The graph shows me how different disciplines are related or at least how current research in different fields is related. I saw many of the leads I had traced through the literature in the graph.

Lets suppose you've been trying to find a solution to a problem and no one in your field has done that. Maybe the solution or information leading to a solution can be found in a related area and the graph can be used to find that related area.