Education
Predicting Speech Acts in MOOC Forum Posts
Arguello, Jaime (University of North Carolina at Chapel Hill) | Shaffer, Kyle (University of North Carolina at Chapel Hill)
Students in a Massive Open Online Course (MOOC) interact with each other and the course staff through online discussion forums. While discussion forums play a central role in MOOCs, they also pose a challenge for instructors. The large number of student posts makes it difficult for an instructor to know where to intervene to answer questions, resolve issues, and provide feedback. In this work, we focus on automatically predicting speech acts in MOOC forum posts. Our speech act categories describe the purpose or function of the post in the ongoing discussion. Specifically, we address three main research questions. First, we investigate whether crowdsourced workers can reliably label MOOC forum posts using our speech act definitions. Second, we investigate whether our speech acts can help predict instructor interventions and assignment completion and performance. Finally, we investigate which types of features (derived from the post content, author, and surrounding context) are most effective for predicting our different speech act categories.
Iterative Regularization for Learning with Convex Loss Functions
Lin, Junhong, Rosasco, Lorenzo, Zhou, Ding-Xuan
We consider the problem of supervised learning with convex loss functions and propose a new form of iterative regularization based on the subgradient method. Unlike other regularization approaches, in iterative regularization no constraint or penalization is considered, and generalization is achieved by (early) stopping an empirical iteration. We consider a nonparametric setting, in the framework of reproducing kernel Hilbert spaces, and prove finite sample bounds on the excess risk under general regularity conditions. Our study provides a new class of efficient regularized learning algorithms and gives insights on the interplay between statistics and optimization in machine learning.
Nonparametric Relational Topic Models through Dependent Gamma Processes
Xuan, Junyu, Lu, Jie, Zhang, Guangquan, Da Xu, Richard Yi, Luo, Xiangfeng
Traditional Relational Topic Models provide a way to discover the hidden topics from a document network. Many theoretical and practical tasks, such as dimensional reduction, document clustering, link prediction, benefit from this revealed knowledge. However, existing relational topic models are based on an assumption that the number of hidden topics is known in advance, and this is impractical in many real-world applications. Therefore, in order to relax this assumption, we propose a nonparametric relational topic model in this paper. Instead of using fixed-dimensional probability distributions in its generative model, we use stochastic processes. Specifically, a gamma process is assigned to each document, which represents the topic interest of this document. Although this method provides an elegant solution, it brings additional challenges when mathematically modeling the inherent network structure of typical document network, i.e., two spatially closer documents tend to have more similar topics. Furthermore, we require that the topics are shared by all the documents. In order to resolve these challenges, we use a subsampling strategy to assign each document a different gamma process from the global gamma process, and the subsampling probabilities of documents are assigned with a Markov Random Field constraint that inherits the document network structure. Through the designed posterior inference algorithm, we can discover the hidden topics and its number simultaneously. Experimental results on both synthetic and real-world network datasets demonstrate the capabilities of learning the hidden topics and, more importantly, the number of topics.
Distributed Online Learning via Cooperative Contextual Bandits
Tekin, Cem, van der Schaar, Mihaela
In this paper we propose a novel framework for decentralized, online learning by many learners. At each moment of time, an instance characterized by a certain context may arrive to each learner; based on the context, the learner can select one of its own actions (which gives a reward and provides information) or request assistance from another learner. In the latter case, the requester pays a cost and receives the reward but the provider learns the information. In our framework, learners are modeled as cooperative contextual bandits. Each learner seeks to maximize the expected reward from its arrivals, which involves trading off the reward received from its own actions, the information learned from its own actions, the reward received from the actions requested of others and the cost paid for these actions - taking into account what it has learned about the value of assistance from each other learner. We develop distributed online learning algorithms and provide analytic bounds to compare the efficiency of these with algorithms with the complete knowledge (oracle) benchmark (in which the expected reward of every action in every context is known by every learner). Our estimates show that regret - the loss incurred by the algorithm - is sublinear in time. Our theoretical framework can be used in many practical applications including Big Data mining, event detection in surveillance sensor networks and distributed online recommendation systems.
Early Steps Towards Web Scale Information Extraction with LODIE
Gentile, Anna Lisa (The University of Sheffield) | Zhang, Ziqi (The University of Sheffield) | Ciravegna, Fabio (The University of Sheffield)
Information extraction (IE) is the technique for transforming unstructured textual data into structured representation that can be understood by machines. The exponential growth of the Web generates an exceptional quantity of data for which automatic knowledge capture is essential. This work describes the methodology for web scale information extraction in the LODIE project (linked open data information extraction) and highlights results from the early experiments carried out in the initial phase of the project. LODIE aims to develop information extraction techniques able to scale at web level and adapt to user information needs. The core idea behind LODIE is the usage of linked open data, a very large-scale information resource, as a ground-breaking solution for IE, which provides invaluable annotated data on a growing number of domains. This article has two objectives. First, describing the LODIE project as a whole and depicting its general challenges and directions. Second, describing some initial steps taken towards the general solution, focusing on a specific IE subtask, wrapper induction.
Reports of the Workshops Held at the Tenth AAAI Conference on Artificial Intelligence and Interactive Digital Entertainment
Barnes, Tiffany (North Carolina State University) | Bown, Oliver (University of Sydney) | Buro, Michael (University of Alberta) | Cook, Michael (Goldsmiths College, University of London) | Eigenfeldt, Arne (Simon Fraser University) | Muรฑoz-Avila, Hรฉctor (Lehigh University) | Ontaรฑรณn, Santiago (Drexel University) | Pasquier, Philippe (Simon Fraser University) | Tomuro, Noriko (DePaul University) | Young, R. Michael (North Carolina State University) | Zook, Alexander (Georgia Institute of Technology)
The AIIDE-14 Workshop program was held Friday and Saturday, October 3โ4, 2014 at North Carolina State University in Raleigh, North Carolina. The workshop program included five workshops covering a wide range of topics. The titles of the workshops held Friday were Games and Natural Language Processing, and Artificial Intelligence in Adversarial Real-Time Games. The titles of the workshops held Saturday were Diversity in Games Research, Experimental Artificial Intelligence in Games, and Musical Metacreation. This article presents short summaries of those events.
Reports of the AAAI 2014 Conference Workshops
Albrecht, Stefano V. (University of Edinburgh) | Barreto, Andrรฉ M. S. (Brazilian National Laboratory for Scientific Computing) | Braziunas, Darius (Kobo Inc.) | Buckeridge, David L. (McGill University) | Cuayรกhuitl, Heriberto (Heriot-Watt University) | Dethlefs, Nina (Heriot-Watt University) | Endres, Markus (University of Augsburg) | Farahmand, Amir-massoud (Carnegie Mellon University) | Fox, Mark (University of Toronto) | Frommberger, Lutz (University of Bremen) | Ganzfried, Sam (Carnegie Mellon University) | Gil, Yolanda (University of Southern California) | Guillet, Sรฉbastien (Universitรฉ du Quรฉbec ร Chicoutimi) | Hunter, Lawrence E. (University of Colorado School of Medicine) | Jhala, Arnav (University of California Santa Cruz) | Kersting, Kristian (Technical University of Dortmund) | Konidaris, George (Massachusetts Institute of Technology) | Lecue, Freddy (IBM Research) | McIlraith, Sheila (University of Toronto) | Natarajan, Sriraam (Indiana University) | Noorian, Zeinab (University of Saskatchewan) | Poole, David (University of British Columbia) | Ronfard, Rรฉmi (University of Grenoble) | Saffiotti, Alessandro (Orebro University) | Shaban-Nejad, Arash (McGill University) | Srivastava, Biplav (IBM Research) | Tesauro, Gerald (IBM Research) | Uceda-Sosa, Rosario (IBM Research) | Broeck, Guy Van den (Katholieke Universiteit Leuven) | Otterlo, Martijn van (Radboud University Nijmegen) | Wallace, Byron C. (University of Texas) | Weng, Paul (Pierre and Marie Curie University) | Wiens, Jenna (University of Michigan) | Zhang, Jie (Nanyang Technological University)
The AAAI-14 Workshop program was held Sunday and Monday, July 27โ28, 2012, at the Quรฉbec City Convention Centre in Quรฉbec, Canada. Canada. The AAAI-14 workshop program included fifteen workshops covering a wide range of topics in artificial intelligence. The titles of the workshops were AI and Robotics; Artificial Intelligence Applied to Assistive Technologies and Smart Environments; Cognitive Computing for Augmented Human Intelligence; Computer Poker and Imperfect Information; Discovery Informatics; Incentives and Trust in Electronic Communities; Intelligent Cinematography and Editing; Machine Learning for Interactive Systems: Bridging the Gap between Perception, Action and Communication; Modern Artificial Intelligence for Health Analytics; Multiagent Interaction without Prior Coordination; Multidisciplinary Workshop on Advances in Preference Handling; Semantic Cities โ Beyond Open Data to Models, Standards and Reasoning; Sequential Decision Making with Big Data; Statistical Relational AI; and The World Wide Web and Public Health Intelligence. This article presents short summaries of those events.
SKILL: A System for Skill Identification and Normalization
Zhao, Meng (Careerbuilder.com) | Javed, Faizan (CareerBuilder.com) | Jacob, Ferosh (CareerBuilder.com) | McNair, Matt (CareerBuilder.com)
Named Entity Recognition (NER) and Named Entity Normalization (NEN) refer to the recognition and normalization of raw texts to known entities. From the perspective of recruitment innovation, professional skill characterization and normalization render human capital data more meaningful both commercially and socially. Accurate and detailed normalization of skills is the key for the predictive analysis of labor market dynamics. Such analytics help bridge the skills gap between employers and candidate workers by matching the right talent for the right job and identifying in-demand skills for workforce training programs. This can also work towards the social goal of providing more job opportunities to the community. In this paper we propose an automated approach for skill entity recognition and optimal normalization. The proposed system has two components: 1) Skills taxonomy generation, which employs vocational skill related sections of resumes and Wikipedia categories to define and develop a taxonomy of professional skills; 2) Skills tagging, which leverages properties of semantic word vectors to recognize and normalize relevant skills in input text. By sampling based end-user evaluation, the current system attains 91% accuracy on the taxonomy generation and 82% accuracy on the skills tagging tasks. The beta version of the system is currently applied in various big data and business intelligence applications for workforce analytics and career track projections at CareerBuilder.
Elementary School Science and Math Tests as a Driver for AI: Take the Aristo Challenge!
Clark, Peter (Allen Institute for AI)
While there has been an explosion of impressive, data-driven AI applications in recent years, machines still largely lack a deeper understanding of the world to answer questions that go beyond information explicitly stated in text, and to explain and discuss those answers. To reach this next generation of AI applications, it is imperative to make faster progress in areas of knowledge, modeling, reasoning, and language. Standardized tests have often been proposed as a driver for such progress, with good reason: Many of the questions require sophisticated understanding of both language and the world, pushing the boundaries of AI, while other questions are easier, supporting incremental progress. In Project Aristo at the Allen Institute for AI, we are working on a specific version of this challenge, namely having the computer pass Elementary School Science and Math exams. Even at this level there is a rich variety of problems and question types, the most difficult requiring significant progress in AI. Here we propose this task as a challenge problem for the community, and are providing supporting datasets. Solutions to many of these problems would have a major impact on the field so we encourage you: Take the Aristo Challenge!