Instructional Material
Modeling Learner’s Cognitive and Metacognitive Strategies in an Open-Ended Learning Environment
Segedy, James René (Vanderbilt University) | Kinnebrew, John S. (Vanderbilt University) | Biswas, Gautam (Vanderbilt University)
The Betty’s Brain computer-based learning system provides an open-ended and choice-rich environment for science learning. Using the learning-by-teaching paradigm paired with feedback and support provided by two pedagogical agents, the system also promotes the development of self-regulated learning strategies to support preparation for future learning. We apply metacognitive learning theories and experiential analysis to interpret the results from previous classroom studies. We propose an integrated cognitive and metacognitive model for effective, self-regulated student learning in the Betty’s Brain environment, and then apply this model to interpret and analyze common suboptimal learning strategies students apply during their learning. This comparison is used to derive feedback for helping learners overcome these difficulties and adopt more effective strategies for regulating their learning. Preliminary results demonstrate that students who were responsive to the feedback had better learning performance.
Reports of the AAAI 2011 Spring Symposia
Buller, Mark (Brown University) | Cuddihy, Paul (General Electric Research) | Davis, Ernest (New York University) | Doherty, Patrick (Linkoping University) | Doshi-Velez, Finale (Massachusetts Institute of Technology) | Erdem, Esra (Sabanci University) | Fisher, Douglas (Vanderbilt University) | Green, Nancy (University of North Carolina, Greensboro) | Hinkelmann, Knut (University of Applied Sciences Northwestern Switzerland FHNW) | Maher, Mary Lou (University of Maryland) | McLurkin, James (Rice University) | Maheswaran, Rajiv (University of Southern California) | Rubinelli, Sara (University of Lucerne) | Schurr, Nathan (Aptima, Inc.) | Scott, Donia (University of Sussex) | Shell, Dylan (Texas A&M University) | Szekely, Pedro (University of Southern California) | Thönssen, Barbara (University of Applied Sciences Northwestern Switzerland FHNW) | Urken, Arnold B. (University of Arizona)
The titles of the eight symposia were Artificial Intelligence and Health Communication, Artificial Intelligence and Sustainable Design, Artificial Intelligence for Business Agility, Computational Physiology, Help Me Help You: Bridging the Gaps in Human-Agent Collaboration, Logical Formalizations of Commonsense Reasoning, Multirobot Systems and Physical Data Structures, and Modeling Complex Adaptive Systems As If They Were Voting Processes. The goal of the Artificial Intelligence and Health Communication symposium was to advance the conceptual design of automated systems that provide health services to patients and consumers through interdisciplinary insight from artificial intelligence, health communication and related areas of communication studies, discourse studies, public health, and psychology. There is a large and growing interest in the development of automated systems to provide health services to patients and consumers. In the last two decades, applications informed by research in health communication have been developed, for example, for promoting healthy behavior and for managing chronic diseases. While the value that these types of applications can offer to the community in terms of cost, access, and convenience is clear, there are still major challenges facing design of effective health communication systems. Overall, the participants found the format of the symposium engaging and constructive, and they The symposium was organized around five main expressed the desire to continue this initiative in concepts: (1) Patient empowerment and education further events.
Bayesian Optimization for Adaptive MCMC
Mahendran, Nimalan, Wang, Ziyu, Hamze, Firas, de Freitas, Nando
This paper proposes a new randomized strategy for adaptive MCMC using Bayesian optimization. This approach applies to non-differentiable objective functions and trades off exploration and exploitation to reduce the number of potentially costly objective function evaluations. We demonstrate the strategy in the complex setting of sampling from constrained, discrete and densely connected probabilistic graphical models where, for each variation of the problem, one needs to adjust the parameters of the proposal mechanism automatically to ensure efficient mixing of the Markov chains.
Representing and Reasoning with Qualitative Preferences for Compositional Systems
Santhanam, G. R., Basu, S., Honavar, V.
Many applications, e.g., Web service composition, complex system design, team formation, etc., rely on methods for identifying collections of objects or entities satisfying some functional requirement. Among the collections that satisfy the functional requirement, it is often necessary to identify one or more collections that are optimal with respect to user preferences over a set of attributes that describe the non-functional properties of the collection. We develop a formalism that lets users express the relative importance among attributes and qualitative preferences over the valuations of each attribute. We define a dominance relation that allows us to compare collections of objects in terms of preferences over attributes of the objects that make up the collection. We establish some key properties of the dominance relation. In particular, we show that the dominance relation is a strict partial order when the intra-attribute preference relations are strict partial orders and the relative importance preference relation is an interval order. We provide algorithms that use this dominance relation to identify the set of most preferred collections. We show that under certain conditions, the algorithms are guaranteed to return only (sound), all (complete), or at least one (weakly complete) of the most preferred collections. We present results of simulation experiments comparing the proposed algorithms with respect to (a) the quality of solutions (number of most preferred solutions) produced by the algorithms, and (b) their performance and efficiency. We also explore some interesting conjectures suggested by the results of our experiments that relate the properties of the user preferences, the dominance relation, and the algorithms.
Convergence rates of efficient global optimization algorithms
Efficient global optimization is the problem of minimizing an unknown function f, using as few evaluations f(x) as possible. It can be considered as a continuum-armed bandit problem, with noiseless data and simple regret. Expected improvement is perhaps the most popular method for solving this problem; the algorithm performs well in experiments, but little is known about its theoretical properties. Implementing expected improvement requires a choice of Gaussian process prior, which determines an associated space of functions, its reproducing-kernel Hilbert space (RKHS). When the prior is fixed, expected improvement is known to converge on the minimum of any function in the RKHS. We begin by providing convergence rates for this procedure. The rates are optimal for functions of low smoothness, and we modify the algorithm to attain optimal rates for smoother functions. For practitioners, however, these results are somewhat misleading. Priors are typically not held fixed, but depend on parameters estimated from the data. For standard estimators, we show this procedure may never discover the minimum of f. We then propose alternative estimators, chosen to minimize the constants in the rate of convergence, and show these estimators retain the convergence rates of a fixed prior.
The SeaLion has Landed: An IDE for Answer-Set Programming---Preliminary Report
Oetsch, Johannes, Pührer, Jörg, Tompits, Hans
We report about the current state and designated features of the tool SeaLion, aimed to serve as an integrated development environment (IDE) for answer-set programming (ASP). A main goal of SeaLion is to provide a user-friendly environment for supporting a developer to write, evaluate, debug, and test answer-set programs. To this end, new support techniques have to be developed that suit the requirements of the answer-set semantics and meet the constraints of practical applicability. In this respect, SeaLion benefits from the research results of a project on methods and methodologies for answer-set program development in whose context SeaLion is realised. Currently, the tool provides source-code editors for the languages of Gringo and DLV that offer syntax highlighting, syntax checking, and a visual program outline. Further implemented features are support for external solvers and visualisation as well as visual editing of answer sets. SeaLion comes as a plugin of the popular Eclipse platform and provides itself interfaces for future extensions of the IDE.
A sticky HDP-HMM with application to speaker diarization
Fox, Emily B., Sudderth, Erik B., Jordan, Michael I., Willsky, Alan S.
We consider the problem of speaker diarization, the problem of segmenting an audio recording of a meeting into temporal segments corresponding to individual speakers. The problem is rendered particularly difficult by the fact that we are not allowed to assume knowledge of the number of people participating in the meeting. To address this problem, we take a Bayesian nonparametric approach to speaker diarization that builds on the hierarchical Dirichlet process hidden Markov model (HDP-HMM) of Teh et al. [J. Amer. Statist. Assoc. 101 (2006) 1566--1581]. Although the basic HDP-HMM tends to over-segment the audio data---creating redundant states and rapidly switching among them---we describe an augmented HDP-HMM that provides effective control over the switching rate. We also show that this augmentation makes it possible to treat emission distributions nonparametrically. To scale the resulting architecture to realistic diarization problems, we develop a sampling algorithm that employs a truncated approximation of the Dirichlet process to jointly resample the full state sequence, greatly improving mixing rates. Working with a benchmark NIST data set, we show that our Bayesian nonparametric architecture yields state-of-the-art speaker diarization results.
Error Identification and Correction in Human Computation: Lessons from the WPA
Grier, David Alan (George Washington University)
Human computing promises new capabilities that cannot be easily provided by computing machinery. However, humans are less disciplined than their mechanical counterparts and hence are liable to produce accidental or deliberate mistakes. As we start to develop regimes for identifying and correcting errors in human computation, we find an important model in the computing groups that operated at the start of the 20th century.
Lightweight Adaptation in Model-Based Reinforcement Learning
Torrey, Lisa (St. Lawrence University)
Reinforcement learning algorithms can train an agent to operate successfully in a stationary environment. Most real-world environments, however, are subject to change over time. Research in the areas of transfer learning and lifelong learning addresses this problem by developing new algorithms that allow agents to adapt to environment change. Current trends in this area include model-free learning and data-driven adaptation methods. This paper explores in the opposite direction of those trends. Arguing that model-based algorithms may be better suited to the problem, it looks at adaptation in the context of model-based learning. Noting that standard algorithms themselves have some built-in capability for adaptation, it analyzes when and why a standard algorithm struggles to adapt to environment change. Then it experiments with lightweight and straightforward methods for adapting effectively.
The Importance of Selective Knowledge Transfer for Lifelong Learning
Eaton, Eric (Bryn Mawr College) | Lane, Terran (University of New Mexico)
Versatile agents situated in rich, dynamic environments must It is not necessarily possible to select the source knowledge be capable of continually learning and refining their knowledge to transfer to a new target task by examining only the surface through experience. These agents will face a variety of similarities between the tasks. The selection must support learning tasks, and can transfer knowledge between tasks to the process of knowledge transfer by choosing source improve performance and accelerate learning. In this context, knowledge based on whether it will transfer well to the target a learning task can be as simple as discovering the effects task. In our previous work, we developed methods that of an operator on the environment, or as complex as accomplishing identify the source knowledge to transfer based on this concept a specific goal -- anything that can be learned of transferability to the target task. Intuitively, transferability can be considered a task. As the agent experiences and learns is the amount that the transferred information is a model for each task, it gains access to new data and knowledge.