Goals and Actions in Natural Language Instructions

Human agents are extremely flexible in dealing with Natural Language instructions: they are able both to adapt the plan they are developing to the input instructions, and vice versa, to adapt the input instructions to the plan they are developing. Borrowing the term from [Lewis 1979], I call this two-way adaptation process accommodation. In this proposal, I first define accommodation in the context of processing instructions. I then provide evidence for the particular inferences I advocate, and for the further claim that such inferences are directed by the goal to achieve which certain action is performed. The evidence I provide comes from my analysis of naturally occurring instructions, and in particular of purpose clauses and of negative imperatives. Finally, I propose a computational model of instructions able to support accommodation inferences. Such model is composed of: a speaker / hearer model of imperatives, based on the one presented in [Cohen and Levesque 90]; an action representation formalism based on a hybrid system, á la KRYPTON [Brachman et al. 1983a], whose primitives are those proposed in [Jackendoff 1990]; and inference mechanisms that contribute to building the structure of the intentions that the agent develops while interpreting instructions

Flexibly Instructable Agents

This paper presents an approach to learning from situated, interactive tutorial instruction within an ongoing agent. Tutorial instruction is a flexible (and thus powerful) paradigm for teaching tasks because it allows an instructor to communicate whatever types of knowledge an agent might need in whatever situations might arise. To support this flexibility, however, the agent must be able to learn multiple kinds of knowledge from a broad range of instructional interactions. Our approach, called situated explanation, achieves such learning through a combination of analytic and inductive techniques. It combines a form of explanation-based learning that is situated for each instruction with a full suite of contextually guided responses to incomplete explanations. The approach is implemented in an agent called Instructo-Soar that learns hierarchies of new tasks and other domain knowledge from interactive natural language instructions. Instructo-Soar meets three key requirements of flexible instructability that distinguish it from previous systems: (1) it can take known or unknown commands at any instruction point; (2) it can handle instructions that apply to either its current situation or to a hypothetical situation specified in language (as in, for instance, conditional instructions); and (3) it can learn, from instructions, each class of knowledge it uses to perform tasks.Comment: See http://www.jair.org/ for any accompanying file

Generating Effective Instructions: Knowing When to Stop

One aspect of Natural Language generation is describing entities so that they are distinguished from all other entities. Entities include objects, events, actions, and states. Much attention has been paid to objects and the generation of their referring expressions (descriptions meant to pick out or refer to an entity). However, a growing area of research is the automated generation of instruction manuals and an important part of generating instructions is distinguishing the actions that are to be carried out from other possible actions. One distinguishing feature is an action\u27s termination, or when the performance of the action is to stop. My dissertation work focuses on generating action descriptions from action information using the SPUD generation algorithm developed here at Penn by Matthew Stone. In my work, I concentrate on the generation of expressions of termination information as part of action descriptions. The problems I address include how termination information is represented in action information and expressed in Natural Language, how to determine when an action description allows the reader to understand how to perform the action correctly, and how to generate the appropriate description of action information

Deictic Reference and Discourse Structure

Research on the factors and processes involved in pronoun interpretation has to date concentrated on anaphoric pronouns. Results have supported the now widely-held view that discourse understanding involves the creation of a partial, mental model of the situation described through the discourse. Anaphoric pronouns are taken to refer to elements of that model (often called discourse referents or discourse entities), usually ones that have, at the moment of referring, some special focus status. This paper examines deictic pronouns - in particular, ones that refer to the interpretation of one or more clauses. I argue that referents for these pronouns must come from the interpretations of discourse segments on the right frontier of an evolving structure representing the discourse. Under the assumption that reference is always to an individual, this implies that discourse segment interpretations must also be part of the evolving discourse model. I discuss this in the last section of the paper

Social identities and law students\u27 writing

This paper argues that social identities, discursively speaking, consist of &lsquo;positions&rsquo; that are individuated by distinctive linguistic features. These include distinctive patterns of representation indicated by clause structure and type, a set of priorities for attending to what is important indicated by thematic structure, and an orientation to the represented world and to self as indicated by modality, propositional attitudes and tense. A social identity comprises an array of these often contradictory &lsquo;positions&rsquo; associated with a social or professional role. A person&rsquo;s identity is constituted dynamically by the way they &lsquo;reconcile&rsquo; the various positions that make up the social identity, and also, as Archer and Ivanic argue, by the way they reconcile a social with a personal or autobiographical identity. It is argued that this process of reconciliation gives clues about identity formation in the traces it leaves in grammatical texture.This paper uses a simulated letter of advice to a client written by a group of first year law students to explore the discursive construction of social or professional identity. This letter is poorly written and full of grammatical mistakes and infelicities. It is argued that the mistakes provide a linguistic trace of the students&rsquo; struggle to reconcile the conflicting roles and positions they occupy as authors of the letter. In particular the students&rsquo; problems result from a struggle to reconcile their multiple positions as: students writing for assessment by a tutor about a legal problem, as a simulated firm of solicitors advising to a client, and as potential litigators anticipating the future course of events in their simulated moot court appearance.<br /