A new probabilistic plan recognition algorithm based on string rewriting

Abstract

This document formalizes and discusses the implementation of a new, more efficient probabilistic plan recognition algorithm called Yet Another Probabilistic Plan Recognizer, (Yappr). Yappr is based on weighted model counting, building its models using string rewriting rather than tree adjunction or other tree building methods used in previous work. Since model construction is often the most computationally expensive part of such algorithms, this results in significant reductions in the algorithm’s runtime.