Commentary on Kurt VanLehn's "The behaviour of tutoring systems"

The paper by Kurt VanLehn has been designed for two audiences: one who does not know very much about ITSs and the other who does. The paper has much to offer both audiences. For the former it gives an indication of the educational performance and complexity that ITSs are now able to offer in a way that focuses on the pedagogy and not on the underlying mechanisms. For the latter audience it offers a way of thinking about the nature of ITSs that helps to unify the field and demonstrates common themes across a range of research programmes. The paper is interesting and useful to read and makes many wise points about ITSs and their development. This commentary on the paper is divided into two parts. The first deals with the basic ontology set out in VanLehn's paper and offers some comments on it. The second goes through the paper sequentially and makes some comments on individual sections and subsections (but not all of them)

DEAP-3600 Dark Matter Search at SNOLAB

The DEAP-3600 detector, currently under construction at SNOLAB, has been designed to achieve extremely low background rates from all sources, including 39Ar beta decays, neutron scatters (from internal and external sources), surface alpha contamination and radon. An overview of the detector and its sensitivity are presented.Comment: Proceedings for the 12th International Conference on Topics in Astroparticle and Underground Physics (TAUP 2011

MSAT: A booster for land based mobile radiocommunication networks?

It is demonstrated that the foreseen phenomenal growth of mobilesat services will impact positively existing terrestrial mobile radio services. Mobilesat systems will not displace the existing terrestrial market in the near future, partly due to the high cost of their terminal units and associated airtime, but also due to some technical limitations, such as lack of spectrum efficiency and high susceptibility to shadowing. However, the ubiquity of mobilesat services will open new market to terrestrial radio technologies. The latter is expected to be the most economical way of extending locally mobilesat services to many users. Conversely, mobilesat systems will be used to extend the capabilities of terrestrial radio systems in areas where the former cannot be implemented cost effectively. It is believed that terrestrial mobile network operators using these service extension capabilities will have a competitive advantage over those who do not. Overall, it is expected that emerging mobilesat services, far from being a threat to terrestrial radio systems, will rather provide these with numerous opportunities of incrementing their base market

Construction and abstraction: contrasting methods of supporting model building in learning science

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Modelling human teaching tactics and strategies for tutoring systems

One of the promises of ITSs and ILEs is that they will teach and assist learning in an intelligent manner. Historically this has tended to mean concentrating on the interface, on the representation of the domain and on the representation of the student’s knowledge. So systems have attempted to provide students with reifications both of what is to be learned and of the learning process, as well as optimally sequencing and adjusting activities, problems and feedback to best help them learn that domain. We now have embodied (and disembodied) teaching agents and computer-based peers, and the field demonstrates a much greater interest in metacognition and in collaborative activities and tools to support that collaboration. Nevertheless the issue of the teaching competence of ITSs and ILEs is still important, as well as the more specific question as to whether systems can and should mimic human teachers. Indeed increasing interest in embodied agents has thrown the spotlight back on how such agents should behave with respect to learners. In the mid 1980s Ohlsson and others offered critiques of ITSs and ILEs in terms of the limited range and adaptability of their teaching actions as compared to the wealth of tactics and strategies employed by human expert teachers. So are we in any better position in modelling teaching than we were in the 80s? Are these criticisms still as valid today as they were then? This paper reviews progress in understanding certain aspects of human expert teaching and in developing tutoring systems that implement those human teaching strategies and tactics. It concentrates particularly on how systems have dealt with student answers and how they have dealt with motivational issues, referring particularly to work carried out at Sussex: for example, on responding effectively to the student’s motivational state, on contingent and Vygotskian inspired teaching strategies and on the plausibility problem. This latter is concerned with whether tactics that are effectively applied by human teachers can be as effective when embodied in machine teachers

Using a simulated student to repair difficulties in collaborative learning

We describe the use of a simulated student in a synchronous but distributed collaborative learning environment in the domain of programming. The role of the simulated student is to detect and repair difficulties in collaborative learning amongst the human students, for example when a human student is too passive or when the students start chatting about off-topic conversations. The simulated student intervenes by posting messages in the shared "chat" window, just like the human students and was believed to be another human student by them. The paper describes the rules by which the simulated student operates and briefly outlines an evaluation of the system with university first year programming students. The system proved to be successful both in detecting a range of difficulties and in intervening effectively

Resource reuse in ie-TV

The convergence of communications and information technology within education, as well as more widely, means that concepts developed within ITS & AIED are now applicable to a wider range of wired, and more interestingly 'wireless', technologies. In [1] we outlined the educational rationale of a Broadband User Model (BbUM) that would support the individualisation of the interactions, both between the technology and a user and between collaborating users, for a system able to deliver a variety of resources in a range of media, including interactive TV. At the heart of any such system there needs to be a database of resources from which the user, the educational designer or the system itself, including the user model, can select. Some of these resources will be items that were developed for other purposes, such as self-contained TV programmes, books or simulation programs. Others will be resources developed with such a system in mind. In either case the use and reuse of these resources depends on careful tagging at a level of granularity that enables them to be used both in their entire original form as well as in parts. For example, imagine that a TV programme is being indexed and that it consists of a number of items, originally in a chronological sequence. The tagging might indicate that one item is analagous to another or generalises it. Labelling the items makes explicit some of the implicit pedagogic relationships that underpin the design of the original programme. This enables the possibility of recomposing the TV programme in some other sequence that reflects a different overall pedagogical structure to the original. Moreover, each item is also tagged in terms of its position in some domain scheme. A prototype system has been implemented that employed a database searchable in a variety of ways, including the keywords matched against video/TV captions and/or automatically transcribed speech. Metadata included such fields as ID, title, ownership, media type, format, and duration. Content categorisation included topic, target user group, and interactivity. Form categorisation included problem, concept, description, and explanation or example

A generic framework for video understanding applied to group behavior recognition

This paper presents an approach to detect and track groups of people in video-surveillance applications, and to automatically recognize their behavior. This method keeps track of individuals moving together by maintaining a spacial and temporal group coherence. First, people are individually detected and tracked. Second, their trajectories are analyzed over a temporal window and clustered using the Mean-Shift algorithm. A coherence value describes how well a set of people can be described as a group. Furthermore, we propose a formal event description language. The group events recognition approach is successfully validated on 4 camera views from 3 datasets: an airport, a subway, a shopping center corridor and an entrance hall.Comment: (20/03/2012

Scintillation of thin tetraphenyl butadiene films under alpha particle excitation

The alpha induced scintillation of the wavelength shifter 1,1,4,4-tetraphenyl-1,3-butadiene (TPB) was studied to improve the understanding of possible surface alpha backgrounds in the DEAP dark matter search experiment. We found that vacuum deposited thin TPB films emit 882 +/-210 photons per MeV under alpha particle excitation. The scintillation pulse shape consists of a double exponential decay with lifetimes of 11 +/-5 ns and 275 +/-10ns.Comment: paper submitted to Nuclear Physics

Computer discrimination between diseases of the brain based on MR image features

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