12,122 research outputs found
Algorithmic and Human Teaching of Sequential Decision Tasks
International audienceA helpful teacher can significantly improve the learning rate of a learning agent. Teaching algorithms have been formally studied within the field of Algorithmic Teaching. These give important insights into how a teacher can select the most informative examples while teaching a new concept. However the field has so far focused purely on classification tasks. In this paper we introduce a novel method for optimally teaching sequential decision tasks. We present an algorithm that automatically selects the set of most informative demonstrations and evaluate it on several navigation tasks. Next, we explore the idea of using this algorithm to produce instructions for humans on how to choose examples when teaching sequential decision tasks. We present a user study that demonstrates the utility of such instructions
Interactive Teaching Algorithms for Inverse Reinforcement Learning
We study the problem of inverse reinforcement learning (IRL) with the added
twist that the learner is assisted by a helpful teacher. More formally, we
tackle the following algorithmic question: How could a teacher provide an
informative sequence of demonstrations to an IRL learner to speed up the
learning process? We present an interactive teaching framework where a teacher
adaptively chooses the next demonstration based on learner's current policy. In
particular, we design teaching algorithms for two concrete settings: an
omniscient setting where a teacher has full knowledge about the learner's
dynamics and a blackbox setting where the teacher has minimal knowledge. Then,
we study a sequential variant of the popular MCE-IRL learner and prove
convergence guarantees of our teaching algorithm in the omniscient setting.
Extensive experiments with a car driving simulator environment show that the
learning progress can be speeded up drastically as compared to an uninformative
teacher.Comment: IJCAI'19 paper (extended version
Understanding the Role of Adaptivity in Machine Teaching: The Case of Version Space Learners
In real-world applications of education, an effective teacher adaptively
chooses the next example to teach based on the learner's current state.
However, most existing work in algorithmic machine teaching focuses on the
batch setting, where adaptivity plays no role. In this paper, we study the case
of teaching consistent, version space learners in an interactive setting. At
any time step, the teacher provides an example, the learner performs an update,
and the teacher observes the learner's new state. We highlight that adaptivity
does not speed up the teaching process when considering existing models of
version space learners, such as "worst-case" (the learner picks the next
hypothesis randomly from the version space) and "preference-based" (the learner
picks hypothesis according to some global preference). Inspired by human
teaching, we propose a new model where the learner picks hypotheses according
to some local preference defined by the current hypothesis. We show that our
model exhibits several desirable properties, e.g., adaptivity plays a key role,
and the learner's transitions over hypotheses are smooth/interpretable. We
develop efficient teaching algorithms and demonstrate our results via
simulation and user studies.Comment: NeurIPS 2018 (extended version
Becoming the Expert - Interactive Multi-Class Machine Teaching
Compared to machines, humans are extremely good at classifying images into
categories, especially when they possess prior knowledge of the categories at
hand. If this prior information is not available, supervision in the form of
teaching images is required. To learn categories more quickly, people should
see important and representative images first, followed by less important
images later - or not at all. However, image-importance is individual-specific,
i.e. a teaching image is important to a student if it changes their overall
ability to discriminate between classes. Further, students keep learning, so
while image-importance depends on their current knowledge, it also varies with
time.
In this work we propose an Interactive Machine Teaching algorithm that
enables a computer to teach challenging visual concepts to a human. Our
adaptive algorithm chooses, online, which labeled images from a teaching set
should be shown to the student as they learn. We show that a teaching strategy
that probabilistically models the student's ability and progress, based on
their correct and incorrect answers, produces better 'experts'. We present
results using real human participants across several varied and challenging
real-world datasets.Comment: CVPR 201
Learning to Teach Reinforcement Learning Agents
In this article we study the transfer learning model of action advice under a
budget. We focus on reinforcement learning teachers providing action advice to
heterogeneous students playing the game of Pac-Man under a limited advice
budget. First, we examine several critical factors affecting advice quality in
this setting, such as the average performance of the teacher, its variance and
the importance of reward discounting in advising. The experiments show the
non-trivial importance of the coefficient of variation (CV) as a statistic for
choosing policies that generate advice. The CV statistic relates variance to
the corresponding mean. Second, the article studies policy learning for
distributing advice under a budget. Whereas most methods in the relevant
literature rely on heuristics for advice distribution we formulate the problem
as a learning one and propose a novel RL algorithm capable of learning when to
advise, adapting to the student and the task at hand. Furthermore, we argue
that learning to advise under a budget is an instance of a more generic
learning problem: Constrained Exploitation Reinforcement Learning
Analyzing collaborative learning processes automatically
In this article we describe the emerging area of text classification research focused on the problem of collaborative learning process analysis both from a broad perspective and more specifically in terms of a publicly available tool set called TagHelper tools. Analyzing the variety of pedagogically valuable facets of learners’ interactions is a time consuming and effortful process. Improving automated analyses of such highly valued processes of collaborative learning by adapting and applying recent text classification technologies would make it a less arduous task to obtain insights from corpus data. This endeavor also holds the potential for enabling substantially improved on-line instruction both by providing teachers and facilitators with reports about the groups they are moderating and by triggering context sensitive collaborative learning support on an as-needed basis. In this article, we report on an interdisciplinary research project, which has been investigating the effectiveness of applying text classification technology to a large CSCL corpus that has been analyzed by human coders using a theory-based multidimensional coding scheme. We report promising results and include an in-depth discussion of important issues such as reliability, validity, and efficiency that should be considered when deciding on the appropriateness of adopting a new technology such as TagHelper tools. One major technical contribution of this work is a demonstration that an important piece of the work towards making text classification technology effective for this purpose is designing and building linguistic pattern detectors, otherwise known as features, that can be extracted reliably from texts and that have high predictive power for the categories of discourse actions that the CSCL community is interested in
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