Technology
Automated Decomposition of Game Maps
Halldórsson, Kári (Reykjavik University) | Björnsson, Yngvi (Reykjavik University)
Video game worlds are getting increasingly large and complex. This poses challenges to the game AI for both pathfinding and strategic decisions, not least in real-time strategy games. One way to alleviate the problem is to manually pre-label the game maps with information about regions and critical choke points, which the game AI can then take advantage of. We present a method for automatically decomposing game maps into non-uniform sized regions. The method uses a flooding algorithm at its core and has the benefit, in addition to its effectiveness, to be relatively intuitive both conceptually and in implementing. Empirical evaluation on game maps shows that the automatic decomposition results in intuitive regions of a comparable standard to human-made labeling. Furthermore, we show that our automatic decomposition, when used by a pathfinding algorithm capable of taking advantage of pre-labeled regions, significantly improves search effectiveness.
MARTHA Speaks: Implementing Theory of Mind for More Intuitive Communicative Acts
Gmytrasiewicz, Piotr (University of Illinois at Chicago) | Moe, George (Illinois Mathematics and Science Academy) | Moreno, Adolfo (University of Illinois at Chicago)
The theory of mind is an important human capability that allows us to understand and predict the goals, intents, and beliefs of other individuals. We present an approach to designing intelligent communicative agents based on modeling theories of mind. This can be tricky because other agents may also have their own theories of mind of the first agent, meaning that these mental models are naturally nested in layers. So, to look for intuitive communicative acts, we recursively apply a planning algorithm in each of these nested layers, looking for possible plans of action as well as their hypothetical consequences, which include the reactions of other agents; we propose that truly intelligent communicative acts are the ones which produce a state of maximum decision theoretic utility according to the entire theory of mind. We implement these ideas using Java and OpenCyc in an attempt to create an assistive AI we call MARTHA. We demonstrate MARTHA's capabilities with two motivating examples: helping the user buy a sandwich and helping the user search for an activity. We see that, in addition to being a personal assistant, MARTHA can be extended to other assistive fields, such as finance, research, and government.
Towards Robot Adaptability in New Situations
Boteanu, Adrian (Worcester Polytechnic Institute) | Kent, David (Worcester Polytechnic Institute) | Mohseni-Kabir, Anahita (Worcester Polytechnic Institute) | Rich, Charles (Worcester Polytechnic Institute) | Chernova, Sonia (Worcester Polytechnic Institute)
We present a system that integrates robot task execution with user input and feedback at multiple abstraction levels in order to achieve greater adaptability in new environments. The user can specify a hierarchical task, with the system interactively proposing logical action groupings within the task. During execution, if tasks fail because objects specified in the initial task description are not found in the environment, the robot proposes substitutions autonomously in order to repair the plan and resume execution. The user can assist the robot by reviewing substitutions. Finally, the user can train the robot to recognize and manipulate novel objects, either during training or during execution. In addition to this single-user scenario, we propose extensions that leverage crowdsourced input to reduce the need for direct user feedback.
A Formal Account of Deception
Sakama, Chiaki (Wakayama University)
This study focuses on the question: "What are the computational formalisms at the heart of deceptive and counter-deceptive machines?" We formulate deception using a dynamic epistemic logic. Three different types of deception are considered: deception by lying, deception by bluffing and deception by truth-telling, depending on whether a speaker believes what he/she says or not. Next we consider various situations where an act of deceiving happens. Intentional deception is accompanied by a speaker's intent to deceive. Indirect deception happens when false information is carried over from person to person. Self-deception is an act of deceiving the self. We investigate formal properties of different sorts of deception.
Toward Characters Who Observe, Tell, Misremember, and Lie
Ryan, James Owen (University of California, Santa Cruz) | Summerville, Adam (University of California, Santa Cruz) | Mateas, Michael (University of California, Santa Cruz) | Wardrip-Fruin, Noah (University of California, Santa Cruz)
Knowledge and its attendant phenomena are central to human storytelling and to the human experience more generally, but we find very few games that revolve around these concerns. This works to preclude a whole class of narrative experiences in games, and it also damages character believability. In this paper, we present an AI framework that supports gameplay with non-player characters who observe and form knowledge about the world, propagate knowledge to other characters, misremember and forget knowledge, and lie. We outline this framework through the lens of a gameplay experience that is intended to showcase it, called Talk of the Town, which we are currently developing. From a review of earlier projects, we find that our system has a novel combination of features found only independently across other systems, and that it is among the first to support character memory fallibility.
Temporal and Object Relations in Unsupervised Plan and Activity Recognition
Freedman, Richard G. (University of Massachusetts Amherst) | Jung, Hee-Tae (University of Massachusetts Amherst) | Zilberstein, Shlomo (University of Massachusetts Amherst)
We consider ways to improve the performance of unsupervised plan and activity recognition techniques by considering temporal and object relations in addition to postural data. Temporal relationships can help recognize activities with cyclic structure and are often implicit because plans have degrees of ordering actions. Relations with objects can help disambiguate observed activities that otherwise share a user's posture and position. We develop and investigate graphical models that extend the popular latent Dirichlet allocation approach with temporal and object relations, examine the relative performance and runtime trade-offs using a standard dataset, and consider the cost/benefit trade-offs these extensions offer in the context of human-robot and humancomputer interaction.
Toward Natural Language Generation by Humans
Ryan, James Owen (University of California, Santa Cruz) | Fisher, Andrew Max (University of California, Santa Cruz) | Owen-Milner, Taylor (University of California, Santa Cruz) | Mateas, Michael (University of California, Santa Cruz) | Wardrip-Fruin, Noah (University of California, Santa Cruz)
Natural language generation (NLG) has been featured in at most a handful of shipped games and interactive stories. This is certainly due to it being a very specialized practice, but another contributing factor is that the state of the art today, in terms of content quality, is simply inadequate. The major benefits of NLG are its alleviation of authorial burden and the capability it gives to a system of generating state-bespoke content, but we believe we can have these benefits without actually employing a full NLG pipeline. In this paper, we present the preliminary design of Expressionist, an in-development mixed-initiative authoring tool that instantiates an authoring scheme residing somewhere between conventional NLG and conventional human content authoring. In this scheme, a human author plays the part of an NLG module in that she starts from a set of deep representations constructed for the game or story domain and proceeds to specify dialogic content that may express those representations. Rather than authoring static dialogue, the author defines a probabilistic context-free grammar that yields templated dialogue. This allows a human author to still harness a computer's generativity, but in a capacity in which it can be trusted: operating over probabilities and treelike control structures. Additional features of Expressionist's design include arbitrary markup and realtime feedback showing currently valid derivations.
Sarah and Sally: Creating a Likeable and Competent AI Sidekick for a Videogame
Cerny, Martin (Charles University in Prague)
Creating reasonable AI for sidekicks in games has proven to be a difficult challenge synthetizing player modelling and cooperative planning, both being problems hard by themselves. In this paper, we experiment with designing around these problems: we propose a cooperative puzzle-platformer game that was designed to look similarly to the mainstream of the genre, but to allow for an easy implementation of a quality sidekick AI, letting us test player reactions to the AI. The game was designed so that it is easy for the AI to find optimal solutions while the problem is relatively hard for a human player. We gathered survey responses from players who played the game online (N=28). While the AI sidekick was reported as likeable and helpful, players still reported greater enjoyment of the game when they were allowed to control the sidekick themselves. These findings indicate that the AI itself is not the only obstacle to truly enjoyable gameplay with an AI sidekick.
Toward Adversarial Online Learning and the Science of Deceptive Machines
Abramson, Myriam (US Naval Research Laboratory)
Intelligent systems rely on pattern recognition and signature-based approaches for a wide range of sensors enhancing situational awareness. For example, autonomous systems depend on environmental sensors to perform their tasks and secure systems depend on anomaly detection methods. The availability of large amount of data requires the processing of data in a “streaming” fashion with online algorithms. Yet, just as online learning can enhance adaptability to a non-stationary environment, it introduces vulnerabilities that can be manipulated by adversaries to achieve their goals while evading detection. Although human intelligence might have evolved from social interactions, machine intelligence has evolved as a human intelligence artifact and been kept isolated to avoid ethical dilemmas. As our adversaries become sophisticated, it might be time to revisit this question and examine how we can combine online learning and reasoning leading to the science of deceptive and counter-deceptive machines.