Abstract: A navigation graph may be generated by performing an Abstract Syntax Tree (AST) Conversion on machine-readable or machine-generated source information to generate a navigation graph in AST format with mappings back to original Data Labeling Sources for the source information. The Navigation Graph in AST format includes nodes connected by unidirectional arcs. Each arc is labeled by a cost of traversal and a probability of traversal. Outside entry points to the Navigation Graph in AST format and optimal paths through the Navigation Graph are identified by applying a Directed Graph Filtering Algorithm thereby producing an Optimized Navigation Graph in which the probability of traversal for one or more of the unidirectional arcs is based in part on user behavior information.