Transformation and alignment in similarity

Carl J Hodgetts, Ulrike Hahn, Nick Chater

Research output: Contribution to journalArticlepeer-review


This paper contrasts two structural accounts of psychological similarity: structural alignment (SA) and Representational Distortion (RD). SA proposes that similarity is determined by how readily the structures of two objects can be brought into alignment; RD measures similarity by the complexity of the transformation that "distorts" one representation into the other. We assess RD by defining a simple coding scheme of psychological transformations for the experimental materials. In two experiments, this "concrete" version of RD provides compelling fits of the data and compares favourably with SA. Finally, stepping back from particular models, we argue that perceptual theory suggests that transformations and alignment processes should generally be viewed as complementary, in contrast to the current distinction in the literature.

Original languageEnglish
Pages (from-to)62-79
Number of pages18
Issue number1
Early online date31 Aug 2009
Publication statusPublished - Oct 2009


  • Adolescent
  • Adult
  • Decision Making/physiology
  • Humans
  • Judgment/physiology
  • Models, Psychological
  • Pattern Recognition, Visual/physiology
  • Photic Stimulation
  • Space Perception/physiology

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