ERIC WILLIAMS Chu-Carroll and Carberry As I read the list of giants upon whose shoulders the authors stood, I was mightily impressed. Then I noticed that though Clark was mentioned, his buddy Horvitz was not. I was further dismayed by this upon reading about the evidential support system they designed. It's reasoning under uncertainty - Horvitz's specialty! Worse yet, it's not nearly as nice. I really dislike the discrete certainty measures (strong, weak, etc). RW: Footnote 11 may be relevant. I was also unsure how the logical propositions were constructed from dialog (ie On-Sabatical(x)). RW: I'm not clear either, but discussion on p. 388 may be helpful. CORE seemed awfully complicated to me. I don't know if I was just too tired to absorb its thoroughness, or if they're really trying to swat a fly with a Buick. RW: It seemed quite complicated to me as well, leading me to try to reduce the cognitive load by synthesizing the works at a high level, suppressing the (voluminous) detail. Zukerman and Litman Interesting historical summary. If I wasn't so tired, I might be able to form questions about it. Oh well, c'est la vie. RW: I used it to select the Kashihara et. al and Chu-Carroll & Carberry articles. I don't think the Zukerman & Litman piece is 'merely' historical: it is both analytical and prospective. Walker, et al Mmmmm...gigantic paper number 3...eyes crossing, brain turning to mush.... Interesting ideas. At the risk of beating a dead horse, I'd like to point out that this, too, would mesh well with Horvitz's work. I was also reminded of Diane's reinforcement learning research. RW: Please elaborate: are you thinking of a BN approach applied to SPG or SPR? It's a good thing I lost the other paper cuz I'd be too stupid from exhaustion to read it. ;) RW: Although I read Kashihara numerous times, and that helped, I can't say I reached clarity about it in detail. ================================ ANTONIO ROQUE "Natural Language Processing and User Modeling" p. 151 discusses the need to study which additional advances in machine learning and reasoning under uncertainty are needed to support new capabilities in natural language systems. Given the warning on p. 149 about intuition not being enough to motivate work, how should we go about deciding which advances to pursue? RW: My copy isn't numbered: what section/subsection are you referring to? ================================ AMY SOLLER What hard-core evidence do we have that tailoring dialog to the user via a user model in the specific ways that have been done in the described systems (which seem to very quite widely) is useful? What are the potential consequences if the predictions about the user's knowledge or inclinations are incorrect? RW: I'm not in a position to provide an authoritative response to the first question, and much depends on what one is willing to count as "hard-card evidence." It is certainly possible that the payoff from user-modelling could be quite small in domains where the variability of user characteristics is low and/or the the effect of such variability on some perfromance metric is negligible. In general, however, there is (hard-core?) evidence that adequately individualized responses lead to greater system use. ================================ ALAN BERFIELD Zukerman & Litman Has the community embraced the issues in this paper? Has any work been started yet that attempts to address them? RW: This question is for Diane, I think. Kashihara et al. They don't mention much about the ordering and interaction between the three task stages. For example, if the follow-up stage (stage 2) reveals a misunderstanding, would a system go back to stage 1 again or would the further explanation be a new cycle after stage 3 completes? Also, are they forcing all 3 to always happen? RW: I agree that more discussion about ordering/interaction would have been helpful. It appears to me that the system does not attempt to recognize misunderstandings as such, but rather assesses the match between the evolving Understanding Structure of the student and it's own co-evolving Explanation Structure. My guess is that an impasse is recognized by a lack of change in US. I'm also guessing that an impasse may lead to a follow-up question from student/system concerning a component/complement or a restriction negotiation of the ES by the system if the system inquires about a different component/complement. If by stage 3 you mean restriction negotion, I think it is necessitated only by certain follow-up clarifications by the student. =============================== THERESA WILSON Zukerman & Litman - "Natural Language Processing and User Modeling" This was a good review article that proposed a number of questions of its own and challenges to future research. One challenge that the authors raised was evaulating the contribution of user models and natural language systems in general. As the authors point out, "generally accepted guidelines for the evaluation of user models and natural language systems are still forthcoming." I'm interested in what the class thinks some of these guidelines for evaluation should be. Chu-Carroll & Carberry - "Response Generation in Planning Dialogues" In this paper, the authors give a detailed look at the types of responses typically used in a collaborative negotiation, and they develop a planning system for working with these responses. Has a similar sort of planning been applied to argumentation and non-cooperative dialogues? RW: Stefanie is the expert on CBR. ======================================= STEFANIE BRUNINGHAUS Walker et al.: What is the tradeoff in developing a trainable system? It seems that getting labeled training data is the bottleneck here, but where is the breakeven point in terms of effort for building a rule-based system compared to generating enough training data for a trainable system? RW: I believe that, in this instance (see p. 12), the labeling is done by the SPG, so that labeling itself is not the bottleneck (though created the SPG may be). Chu-Caroll & Carberry: Would case-based reasoning be applicable here? The authors already discuss that unsatisfactory plans are not completely thrown out, but rather repaired (or, one could say, adapted), suggests that CBR could be a good idea. RW: Being completely without knowledge about CBR, I wonder what the cases would be, how they would be acquired by the system, and how it would aid with selecting a justification chain. --