Ronald W. Ferguson

Towards a computational model of sketching

Sketching is a powerful means of interpersonal communication. While many useful multimodal systems have been created, current systems are far from achieving human-like participation in sketching. A computational model of sketching would help characterize these differences and help us better understand how to overcome them. This paper is a first step towards such a model. We start with an example of a sketching system(nuSketch COA Creator)designed to aid military planners, to provide context and a source of examples. We then describe four dimensions of sketching,visual understanding, conceptual understanding, language understanding,anddrawing,that can be used to characterize the competence of existing systems and identify open problems. The issues involved will be illustrated by examples from our experience with nuSketch. Three research challenges are posed, to serve as milestones towards a computational model of sketching that can explain and replicate human abilities in this area.

Analogy just looks like high level perception: why a domain-general approach to analogical mapping is right

Hofstadter and his colleagues have criticized current accounts of analogy, claiming that such accounts do not accurately capture interactions between processes of representation construction and processes of mapping. They suggest instead that analogy should be viewed as a form of high level perception that encompasses both representation building and mapping as indivisible operations within a single model. They argue speci® cally against SME, our model of analogical matching, on the grounds that it is modular, and oŒer instead programs such as Mitchell and Hofstadters Copycat as examples of the high level perception approach. In this paper we argue against this position on two grounds. First, we demonstrate that most of their speci® c arguments involving SME and Copycat are incorrect. Second, we argue that the claim that analogy is high-level perception, while in some ways an attractive metaphor, is too vague to be useful as a technical proposal. We focus on ® ve issues: (1) how perception relates to analogy,(2) howexibilityarises in analogical processing, (3) whether analogy is a domain-general process, (4) how micro-worlds should be used in the study of analogy, and (5) how best to assess the psychological plausibility of a model of analogy. We illustrate our discussion with examples taken from computer models embodying both views.