Modeling the effects of argument length and validity on inductive and deductive reasoning.

Full Abstract

In an effort to assess models of inductive reasoning and deductive reasoning, the authors, in 3 experiments, examined the effects of argument length and logical validity on evaluation of arguments. In Experiments 1a and 1b, participants were given either induction or deduction instructions for a common set of stimuli. Two distinct effects were observed: Induction judgments were more affected by argument length, and deduction judgments were more affected by validity. In Experiment 2, fluency was manipulated by displaying the materials in a low-contrast font, leading to increased sensitivity to logical validity. Several variants of 1-process and 2-process models of reasoning were assessed against the results. A 1-process model that assumed the same scale of argument strength underlies induction and deduction was not successful. A 2-process model that assumed separate, continuous informational dimensions of apparent deductive validity and associative strength gave the more successful account. (c) 2009 APA, all rights reserved.

Author information

Author/s: Rotello, Caren M (CM); Heit, Evan (E);

Affiliation: Department of Psychology, University of Massachusetts, Box 37710, Amherst, MA 01003, USA. caren(-atsign-)psych.umass.edu

Journal and publication information

Publication Type: Journal Article; Research Support, U.S. Gov't, Non-P.H.S.

Journal: Journal of experimental psychology. Learning, memory, and cognition (J Exp Psychol Learn Mem Cogn), published in United States. (Language: eng)

Reference: 2009-Sep; vol 35 (issue 5) : pp 1317-30

Dates: Created 2009/08/18; Completed 2009/10/08;

PMID: 19686024, status: MEDLINE (last retrieval date: 10/8/2009, IMS Date: )

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

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