Comparing Plan Recognition Algorithms Through Standard Plan Libraries

Frontiers in Artificial Intelligence

Gal Kaminka¹  Reuth Mirsky²  Ran Galun³  Kobi Gal⁴ 

[1] Department of Computer Science, Bar Ilan University, Ramat Gan, Israel;Department of Computer Science, The University of Texas at Austin, Austin, TX, United States;Department of Software and Information Systems Engineering, Ben Gurion University, Be’er Sheva, Israel;School of Informatics, University of Edinburgh, Edinburgh, United Kingdom;

关键词: plan recognition;    standardization;    plan libraries;    theory of mind;    artificial intelligence;   

DOI  :  10.3389/frai.2021.732177

来源: DOAJ

【 摘 要 】

Plan recognition deals with reasoning about the goals and execution process of an actor, given observations of its actions. It is one of the fundamental problems of AI, applicable to many domains, from user interfaces to cyber-security. Despite the prevalence of these approaches, they lack a standard representation, and have not been compared using a common testbed. This paper provides a first step towards bridging this gap by providing a standard plan library representation that can be used by hierarchical, discrete-space plan recognition and evaluation criteria to consider when comparing plan recognition algorithms. This representation is comprehensive enough to describe a variety of known plan recognition problems and can be easily used by existing algorithms in this class. We use this common representation to thoroughly compare two known approaches, represented by two algorithms, SBR and Probabilistic Hostile Agent Task Tracker (PHATT). We provide meaningful insights about the differences and abilities of these algorithms, and evaluate these insights both theoretically and empirically. We show a tradeoff between expressiveness and efficiency: SBR is usually superior to PHATT in terms of computation time and space, but at the expense of functionality and representational compactness. We also show how different properties of the plan library affect the complexity of the recognition process, regardless of the concrete algorithm used. Lastly, we show how these insights can be used to form a new algorithm that outperforms existing approaches both in terms of expressiveness and efficiency.

【 授权许可】

Unknown