Explanation and evidence in informal argument

Sarah K. Brem, Lance J. Rips

Research output: Contribution to journalArticle

122 Scopus citations


A substantial body of evidence shows that people tend to rely too heavily on explanations when trying to justify an opinion. Some research suggests these errors may arise from an inability to distinguish between explanations and the evidence that bears upon them. We examine an alternative account, that many people do distinguish between explanations and evidence, but rely more heavily on unsubstantiated explanations when evidence is scarce or absent. We examine the philosophical and psychological distinctions between explanation and evidence, and show that participants use explanations as a substitute for missing evidence. Experiment 1 replicates the results of other researchers, but further shows that participants generate more evidence when they are not constrained by their lack of data. Merely mentioning a source of data can alter both their evaluation (Experiment 2) and their production (Experiment 3) of explanations and evidence. In Experiment 4, we show that participants can explicitly consider the availability of evidence and other pragmatic factors when evaluating arguments. Finally, we consider the implications of using explanations to replace missing evidence as a strategy in argument.

Original languageEnglish (US)
Pages (from-to)573-604
Number of pages32
JournalCognitive Science
Issue number4
Publication statusPublished - Oct 2000
Externally publishedYes


ASJC Scopus subject areas

  • Language and Linguistics
  • Artificial Intelligence
  • Cognitive Neuroscience
  • Experimental and Cognitive Psychology
  • Human Factors and Ergonomics
  • Linguistics and Language

Cite this

Brem, S. K., & Rips, L. J. (2000). Explanation and evidence in informal argument. Cognitive Science, 24(4), 573-604.