Aspect


Aspect refers to the ways in which the internal shape of an event affects both acceptability and interpretation of the linguistic devices used to describe it. Aspectual inferences seem to depend not only on inherent verb semantics but also on the semantic contributions of their arguments. Aspect has a pervasive effect on interpretation or construal; semantic phenomena that interact with aspect in the interpretation of even the simplest sentence include:

  • the presence of trajectors, landmarks, paths and goals
  • the persistence and reversibility of states
  • the use of effort and intention
  • the force dynamics and/or homogeneity of actions
  • the time scale of reasoning
  • nominal features as animacy, boundedness (mass/count) and quantification

We have developed a dynamic model of aspectual composition, in which:

  • Events are modeled using an active computational representation called x-schemas, an extension of the Petri net formalism that can encode goals, resources and many other features.
  • General aspectual controller schemas are bound to specific action schemas to simulate an event in a context-sensitive manner.
  • Linguistic markers affecting aspect (such as those constraining tense, temporal modifiers, nominals and pragmatic context) can elaborate and constrain event simulations.
The figure below shows an x-schema representation of the event described in Harry is walking to the store. The token in the node marked ongoing corresponds to the progressive aspect of the sentence (i.e., the event is in progress). See [1] for more details.



Papers/Presentations

  1. N. Chang, D. Gildea and S. Narayanan. A Dynamic Model of Aspectual Composition (pdf), presented at CogSci 1998. Also see accompanying slides (pdf).
    Brief introduction to the x-schema representation and the basic aspect controller (as described more fully in Narayanan's thesis); more concrete technical details of ideas proposed in [2,3]; integration with an account of tense.
  2. A Motor- and Image-Schematic Analysis of Aspectual Composition (PDF, postscript), ICSI technical report.
    A longer and older version of [1], more extensive on the linguistics, less on the computational mechanisms. General introduction to the problem of aspect and some of cognitive linguistics. (A similar version was written for a cognitive lingustics seminar and for research in the NTL context, A Cognitive Approach to Aspectual Composition (compressed postscript).
  3. A short, non-technical version of the story (compressed postscript or html), presented at the student session of the 1997 International Cognitive Linguistics Conference in Amsterdam.