Agents
Decision Making with Dynamic Uncertain Events
Kalech, Meir, Reches, Shulamit
When to make a decision is a key question in decision making problems characterized by uncertainty. In this paper we deal with decision making in environments where information arrives dynamically. We address the tradeoff between waiting and stopping strategies. On the one hand, waiting to obtain more information reduces uncertainty, but it comes with a cost. Stopping and making a decision based on an expected utility reduces the cost of waiting, but the decision is based on uncertain information. We propose an optimal algorithm and two approximation algorithms. We prove that one approximation is optimistic - waits at least as long as the optimal algorithm, while the other is pessimistic - stops not later than the optimal algorithm. We evaluate our algorithms theoretically and empirically and show that the quality of the decision in both approximations is near-optimal and much faster than the optimal algorithm. Also, we can conclude from the experiments that the cost function is a key factor to chose the most effective algorithm.
Increasing the Engagement of Conversational Agents through Co-Constructed Storytelling
Battaglino, Cristina (Northeastern University) | Bickmore, Timothy (Northeastern University)
Storytelling can be used by conversational agents in a wide variety of domains to maintain user engagement, both within a single interaction and over dozens or hun- dreds of interactions over time. The majority of agents designed with this ability to date deliver their stories as monologues without user input. However, people rarely tell stories in conversations this way, and instead rely on listener contributions to guide the storytelling process. Corpus-based studies of human-human conversational storytelling have demonstrated greater engagement, in the form of longer stories, when listeners co-construct stories this way. We describe a research framework for the generation and evaluation of co-constructed social stories in the context of task-based conversations, and a study on the effects of degree of user-agent story co-construction on user engagement. We find that users are more en- gaged with storytelling agents that allow them to co- construct stories in a contentful manner by asking ques- tions, compared to co-construction through acknowl- edgments only.
Commitment Semantics for Sequential Decision Making Under Reward Uncertainty
Durfee, Edmund H. (University of Michigan) | Singh, Satinder (University of Michigan)
A commitment represents an agent's intention to attempt to bring about some state of the world that is desired by some agent (possibly itself) in the future. Thus, by making a commitment, an agent is agreeing to make sequential decisions that it believes can cause the desired state to arise. In general, though, an agent's actions will have uncertain outcomes, and thus reaching the desired state cannot be guaranteed. For such sequential decision settings with uncertainty, therefore, commitments can only be probabilistic. We argue that standard notions of commitment are insufficient for probabilistic commitments, and propose a new semantics that judges commitment fulfillment not in terms of whether the agent achieved the desired state, but rather in terms of whether the agent made sequential decisions that in expectation would have achieved the desired state with (at least) the promised probability. We have devised various algorithms that operationalize our semantics, to capture problem contexts with probabilistic commitments arising because action outcomes are uncertain, as well as arising because an agent might realize over time that it does not want to fulfill the commitment.
Toward an Intelligent Agent for Fraud Detection — The CFE Agent
Johnson, Joe (Rensselaer Polytechnic Institute)
One of the primary realms into which artificial intelligence research has ventured is that of psychometric tests. It has been debated since Alan Turing proposed the Turing Test whether performance on tests should serve as the metric by which we should determine whether a machine is intelligent. This is an idea that may either solidify or challenge, depending on the reader's predisposition, one's sense of what artificial intelligence really is. As will be discussed in this paper, there is a history of efforts to create agents that perform well on tests in the spirit of an interpretation of artificial intelligence called ``Psychometric AI''. However, the focus of this paper is to describe a machine agent, hereafter called the CFE Agent, developed in this tradition. The CFE Exam is a gateway to certification in the Association of Certified Fraud Examiners (ACFE), a widely recognized professional credential within the fraud examiner profession. The CFE Agent attempts to emulate the successful performance of a human test taker, using what would appear to be simplistic natural language processing approaches to answer test questions. But it is also hoped that the the reader will be convinced that the same core technologies can be successfully applied within the larger domain of fraud detection. Further work will also be briefly discussed, in which we attempt to take these techniques to the next level, a deeper level, by which we can get a better sense of the knowledge the agent is using, and how that knowledge is being applied to formulate answers.
Complexity of Self-Preserving, Team-Based Competition in Partially Observable Stochastic Games
Allen, Marty (University of Wisconsin-La Crosse)
Partially observable stochastic games (POSGs) are a robust and precise model for decentralized decision making under conditions of imperfect information, and extend popular Markov decision problem models. Complexity results for a wide range of such problems are known when agents work cooperatively to pursue common interests. When agents compete, things are less well understood. We show that under one understanding of rational competition, such problems are complete for the class NEXP^NP. This result holds for any such problem comprised of two competing teams of agents, where teams may be of any size whatsoever.
The MADP Toolbox: An Open-Source Library for Planning and Learning in (Multi-)Agent Systems
Oliehoek, Frans A. (University of Liverpool, University of Amsterdam) | Spaan, Matthijs T. J. (Delft University of Technology) | Robbel, Philipp (Massachusetts Institute of Technology) | Messias, Joao (University of Amsterdam)
This article describes the MultiAgent Decision Process (MADP) toolbox, a software library to support planning and learning for intelligent agents and multiagent systems in uncertain environments. Some of its key features are that it supports partially observable environments and stochastic transition models; has unified support for single- and multiagent systems; provides a large number of models for decision-theoretic decision making, including one-shot decision making (e.g., Bayesian games) and sequential decision making under various assumptions of observability and cooperation, such as Dec-POMDPs and POSGs; provides tools and parsers to quickly prototype new problems; provides an extensive range of planning and learning algorithms for single-and multiagent systems; and is written in C++ and designed to be extensible via the object-oriented paradigm.
Coordination of Human-Robot Teaming with Human Task Preferences
Gombolay, Matthew Craig (Massachusetts Institute of Technology) | Huang, Cindy (Massachusetts Institute of Technology) | Shah, Julie (Massachusetts Institute of Technology)
Advanced robotic technology is opening up the possibility of integrating robots into the human workspace to improve productivity and decrease the strain of repetitive, arduous physical tasks currently performed by human workers. However, coordinating these teams is a challenging problem. We must understand how decision-making authority over scheduling decisions should be shared between team members and how the preferences of the team members should be included. We report the results of a human-subject experiment investigating how a robotic teammate should best incorporate the preferences of human teammates into the team's schedule. We find that humans would rather work with a robotic teammate that accounts for their preferences, but this desire might be mitigated if their preferences come at the expense of team efficiency.
“Sorry, I Can’t Do That”: Developing Mechanisms to Appropriately Reject Directives in Human-Robot Interactions
Briggs, Gordon Michael (Tufts University) | Scheutz, Matthias (Tufts University)
An ongoing goal at the intersection of artificial intelligence In this paper, we briefly present initial work that has (AI), robotics, and human-robot interaction (HRI) is to create been done in the DIARC/ADE cognitive robotic architecture autonomous agents that can assist and interact with human (Schermerhorn et al. 2006; Kramer and Scheutz 2006) to enable teammates in natural and humanlike ways. This is a such a rejection and explanation mechanism. First we multifaceted challenge, involving both the development of discuss the theoretical considerations behind this challenge, an ever-expanding set of capabilities (both physical and algorithmic) specifically the conditions that must be met for a directive to such that robotic agents can autonomously engage be appropriately accepted. Next, we briefly present some of in a variety of useful tasks, as well as the development the explicit reasoning mechanisms developed in order to facilitate of interaction mechanisms (e.g.
Playspecs: Regular Expressions for Game Play Traces
Osborn, Joseph Carter (University of California, Santa Cruz) | Samuel, Ben (University of California, Santa Cruz) | Mateas, Michael (University of California, Santa Cruz) | Wardrip-Fruin, Noah (University of California, Santa Cruz)
We introduce Playspecs, an application of omega-regular expressions to specifying play traces (sequences of game states or events unfolding over time). This connects the automated analysis and model checking of games to the literature on formal software verification via Bu ̈chi automata. We show how to define desirable or undesirable sequences of game events with Playspecs and how associated algorithms can find examples (or prove the impossibility) of such sequences. Playspecs have two main benefits over existing techniques for specifying the behaviors of a game over time. First, they offer a scalable commitment to formal modeling: the same Playspecs can filter existing traces gathered by telemetry, search for satisfying traces using existing game code, or drive formal verification when paired with a logical model of a game. Second, Playspecs' syntax can be customized for the game engine or game in question so designers may write specifications using their game's native vocabulary. We define Playspecs' syntax and semantics (modulo gamespecific customizations) and outline algorithms for each of the applications mentioned above, providing examples from the social simulation game Prom Week and the puzzle game engine PuzzleScript.
The Most Intelligent Robots Are Those that Exaggerate: Examining Robot Exaggeration
Wagner, Alan Richard (Georgia Institute of Technology Research Institute)
This paper presents a model of exaggeration suitable for implementation on a robot. Exaggeration is an interest form of dishonesty in that it serves as a tradeoff between the different costs associated with lying and the reward received by having one’s lie accepted. Moreover, exaggeration offers the deceiver additional control in the form of much the exaggerated statement differs from the truth. We use a color guessing game to examine the different tradeoffs between these costs and rewards and their impact on exaggeration. Our results indicate some amount of exaggeration is the preferred option during most early interactions. Further, because the cost of lying increases linear with the number of lies, exaggeration decreases with additional interactions. We conclude by arguing why social robots must be capable of lying.