If it is true that good problems produce good science, then it will be worthwhile to identify good problems, and even more worthwhile to discover the attributes that make them good problems. This discovery process is necessarily empirical, so we examine several challenge problems, beginning with Turing's famous test, and more than a dozen attributes that challenge problems might have. We are led to a contrast between research strategies -- the successful "divide and conquer" strategy and the promising but largely untested "developmental" strategy -- and we conclude that good challenge problems encourage the latter strategy.

I systems, the importance of controlling the had previously worked in cybernetics, data acquisition, and introduced an new control theory, and pattern recognition, paradigm: active perception. We stated that where we modeled intelligence, perception, we not just see but we also look, and we and action as signal processing.

Learning how to create, test, and revise models is a central skill in scientific reasoning. We argue that qualitative modeling provides an appropriate level of representation for helping middle-school students learn to become modelers. We describe Vmodel, a system we have created that uses visual representations and that enables middle-school students to create qualitative models. We discuss the design of the visual representation language, how Vmodel works, and evidence from school studies that indicate it is successful in helping students.

In recent years, we have witnessed the success of autonomous agents applying machine-learning techniques across a wide range of applications. However, agents applying the same machine-learning techniques in online applications have not been so successful. Even agent-based hybrid recommender systems that combine information filtering techniques with collaborative filtering techniques have been applied with considerable success only to simple consumer goods such as movies, books, clothing, and food. Yet complex, adaptive autonomous agent systems that can handle complex goods such as real estate, vacation plans, insurance, mutual funds, and mortgages have emerged. To a large extent, the reinforcement learning methods developed to aid agents in learning have been more successfully deployed in offline applications. The inherent limitations in these methods have rendered them somewhat ineffective in online applications. In this article, we postulate that a small amount of prior knowledge and human-provided input can dramatically speed up online learning. We demonstrate that our agent HumanE -- with its prior knowledge or "experiences" about the real estate domain -- can effectively assist users in identifying requirements, especially unstated ones, quickly and unobtrusively.

Preference Crystal City, Arlington Virginia, adjacent languages such as RDF and OWL. will be given to student scholars to Washington, DC.

"This summer, three local students will explore News" collection that can be found--complete Warburg school, will spend the Web pages. The only cost of the computers for five to six hours a day, the class is about $300 for a kit, which Gtech Gives Girls Blueprint for Success. May activities to break up the day." The space agency also provided 27, 2004 (www.westuexaminer.com). "The free kits for another 30 online students, best way to increase girls' interest in engineering Girls Build Robots at RoboCamp.

Learning how to create, test, and revise models is a central skill in scientific reasoning. We argue that qualitative modeling provides an appropriate level of representation for helping middle-school students learn to become modelers. We describe Vmodel, a system we have created that uses visual representations and that enables middle-school students to create qualitative models. Software coaches use simple analyses of model structure plus qualitative simulation to provide feedback and explanations. This system has been used in several studies in Chicago public school classrooms, using curricula developed in collaboration with teachers. We discuss the design of the visual representation language, how Vmodel works, and evidence from school studies that indicate it is successful in helping students.

We are pleased to publish this special selection of articles from the Sixteenth Annual Conference on Innovative Applications of Artificial Intelligence (IAAI-04), which occurred July 27-29, 2004 in San Jose, California. IAAI is the premier venue for learning about AI's impact through deployed applications and emerging AI technologies. Case studies of deployed applications with measurable benefits arising from the use of AI technology provide clear evidence of the impact and value of AI technology to today's world. The emerging applications track features technologies that are rapidly maturing to the point of application. The seven articles selected for this special issue are extended versions of the papers that appeared at the conference. Four of the articles describe deployed applications that are already in use in the field. The other three articles, which are from the emerging technology track, were selected because they are particularly innovative and show great potential for deployment.

Six high-level requirements drive the implementation of intelligent synthetic adversaries for training: (1) competence, (2) taskability, (3) observational fidelity, (4) behavior variability, most difficult tasks soldiers perform. Frequent Competence: The adversaries must perform training is an essential element in reducing the tactics and missions humans perform in casualties. For this application, the adversaries' environments is costly and restricted to physical goal is to defend a small multistoried mockups of buildings and small towns. The agents must move Environments (VIRTE) program is developing immersive virtual trainers for military operations through the environment, identify tactically on urbanized terrain (MOUT). In this relevant features (such as escape routes), and trainer, four-person fire teams of U.S. Marines communicate and coordinate with other are situated in a virtual urban environment and agents. Virtual opponents new missions for different training scenarios, are required to populate the environment and and they must change their objectives challenge the trainees. Behavior is not scripted or This article describes the general requirements specific to a particular mission, terrain, or operational for virtual MOUT opponents and our development setting, providing flexibility for operational of synthetic adversaries to meet use.

The paper studies machine learning problems where each example is described using a set of Boolean features and where hypotheses are represented by linear threshold elements. One method of increasing the expressiveness of learned hypotheses in this context is to expand the feature set to include conjunctions of basic features. This can be done explicitly or where possible by using a kernel function. Focusing on the well known Perceptron and Winnow algorithms, the paper demonstrates a tradeoff between the computational efficiency with which the algorithm can be run over the expanded feature space and the generalization ability of the corresponding learning algorithm. We first describe several kernel functions which capture either limited forms of conjunctions or all conjunctions. We show that these kernels can be used to efficiently run the Perceptron algorithm over a feature space of exponentially many conjunctions; however we also show that using such kernels, the Perceptron algorithm can provably make an exponential number of mistakes even when learning simple functions. We then consider the question of whether kernel functions can analogously be used to run the multiplicative-update Winnow algorithm over an expanded feature space of exponentially many conjunctions. Known upper bounds imply that the Winnow algorithm can learn Disjunctive Normal Form (DNF) formulae with a polynomial mistake bound in this setting. However, we prove that it is computationally hard to simulate Winnow's behavior for learning DNF over such a feature set. This implies that the kernel functions which correspond to running Winnow for this problem are not efficiently computable, and that there is no general construction that can run Winnow with kernels.