Issue of Monday, April 16th, 2012
Just a reminder that Monday and Tuesday of this week are holidays at MIT, and no classes will be held (unless otherwise specified). Monday is Patriots’ Day, which commemorates the battles of Lexington and Concord. Tuesday, of course, commemorates the day after the battles of Lexington and Concord. In theory, Wednesday should celebrate the day after Tuesday, but holidays lack the property of recursion.
Speaker: Giorgio Magri (Jean Nicod)
Date/Time: 4/18 (Wed) 5 pm
Title: The OT error-driven ranking model of the acquisition of phonotactics: some computational results
Nine-month-old infants already react differently to licit vs illicit sound combinations, thus displaying knowledge of the target adult phonotactics. Children must thus rely on a remarkably efficient phonotactics learning strategy. What could it look like? According to the error-driven learning model, the learner maintains a current hypothesis of the target adult phonotactics and keeps slightly updating its current hypothesis whenever it makes a mistake on the incoming stream of data from the adult language. This learning model has been endorsed by the Optimality Theoretic (OT) acquisition literature because of its cognitive plausibility: it models the observed acquisition gradualness, as it describes a stepwise progression towards the target adult grammar; it relies on surface phonology without requiring any knowledge of morphology, that plausibly develops later than phonotactics; and it does not impose unrealistic memory requirements, as it only looks at a piece of data at the time without keeping track of previously seen data. Bridging cognitive plausibility with computational soundness, my current project defends the hypothesis that OT error-driven learning provides a proper model of the child acquisition of phonotactics. The project is articulated around five core issues. The first issue concerns convergence: does the model eventually stop making mistakes and settle on a final grammar? The second issue concerns correctness: does the final grammar entertained by the model at convergence indeed capture the target phonotactics? The third issue concerns modeling adequacy: do the learning sequences formally predicted by the model match attested child acquisition paths? The fourth issue concerns robustness and variation: how does the model behave in the presence of noise and how can it make sense of the pervasive phenomenon of child variation? The fifth issue concerns framework selection: how can the choice of the OT framework be justified from a learning theoretic perspective? This talk will provide an overview of the project, with a focus on some recent results concerning the first two issues of convergence and correctness.
Speaker: Ben George
Date/Time: 4/19 (Thu) 10 am
Title: Question Embedding: Varieties of Reducibility and Non-Reducibility
In this talk is an effort to collect some of my recent concerns about question embedding under predicates, like ‘know’, that have both a propositional (1) and a question-oriented (2) use.
1. Anne knows that Maggie destroyed the records.
2. Anne knows who destroyed the records.
A usual assumption, sometimes implicit and sometimes explicit, is that the truth of sentences like (2) is to be evaluated in terms of the facts reported by sentences like (1). That is, most theories of question embedding employ some version of the reducibility assumption in (3).
3. The truth of a sentence like (2) is determined entirely by which answers to the embedded question (‘who destroyed the records?’) are known by the subject (Anne).
In this talk, I briefly introduce some of the (quasi-)formalizations and weakenings of (3) that I and others have suggested, and then introduce three groups of descriptive claims that challenge some or all formulations of (3), with an emphasis on moving beyond the ‘mention some’ cases that I considered before, and engaging with ‘exhaustive’ examples (4, after an example from Lahiri and an observation of Kratzer) and examples involving ‘agree’ (5, after a claim from Beck and Rullmann).
4. The witnesses know which conspirators were present at the secret meeting.
(Truth depends not only on witnesses’ knowledge, but on whether they have any relevant false beliefs.)
5. Robin and Rupert agree on which of their colleagues are spies.
(Truth depends not only on which answers Robin and Rupert agree to, but on which answers they are opinionated about.)
I do not reach any firm conclusions, but attempt to get a sense of the scope of the problem, and suggest a preliminary taxonomy of problem cases.
Speaker: Leon Bergen (Brain & Cognitive Sciences, MIT)
Title: That’s what she (could have) said: How alternative utterances affect language use
Time: Thursday, Apr 19, 12:30-1:45p
(Joint work with Noah Goodman and Roger Levy)
We investigate the effects of alternative utterances on pragmatic interpretation of language. We focus on two specific cases: specificity implicatures (less specific utterances imply the negation of more specific utterances) and Horn implicatures (more complex utterances are assigned to less likely meanings). We present models of these phenomena in terms of recursive social reasoning. Our most sophisticated model is not only able to handle specificity implicature but is also the first formal account of Horn implicatures that correctly predicts human behavior in signaling games with no prior conventions, without appeal to specialized equilibrium selection criteria. Two experiments provide evidence that these implicatures are generated in the absence of prior linguistic conventions or language evolution. Taken together, our modeling and experimental results suggest that the pragmatic effects of alternative utterances can be driven by cooperative social reasoning.
Remember those WCCFL practice talks we announced last week by Coppe van Urk and Hadas Kotek. Last weekend was the real thing, and by all accounts both WCCFL 30 at Santa Cruz and the talks by Coppe (joint with UCLA’s Laura Kalin) and Hadas were great successes.
At the Modality workshop at University of Ottawa this coming weekend, MIT will be represented by invited speaker Sabine Iatridou (an invited speaker); Bronwyn Bjorkman (PhD 2011) and Claire Halpert (In an imperfect world: deriving the typology of counterfactual marking), and Igor Yanovich (Modal hopes and fears: a diachronic case study). Alumna Bridget Copley(PhD 2002, CNRS & Paris 8) will also be presenting a paper at the conference (Wanting good cheese and acting to get it: Anankastic conditionals and intent).