The A search algorithm nds an optimal path through a search graph. It is easily modi ed to return multiple paths in decreasing order of optimality, but it cannot handle conjunctive problems. The AO search algorithm does handle conjunctive problems and nds an optimal subgraph of an acyclic AND/OR graph. However, it returns only one solution and can only handle totally independent conjunctive pro...

In recent years, the problem of association rule mining in transactional data has been well studied. We propose to extend the discovery of classical association rules to the discovery of association rules of conjunctive queries in arbitrary relational data, inspired by the Warmr algorithm, developed by Dehaspe and Toivonen, that discovers association rules over a limited set of conjunctive quer...

A step in ITS often involve multiple skills. Thus a step requiring a conjunction of skills is harder than steps that require requiring each individual skill only. We developed two Item-Response Models – Additive Factor Model (AFM) and Conjunctive Factor Model (CFM) – to model the conjunctive skills in the student data sets. Both models are compared on simulated data sets and a real assessment d...