Psychonomic Bulletin & Review

, Volume 14, Issue 1, pp 3–22

An EZ-diffusion model for response time and accuracy

  • Eric-Jan Wagenmakers
  • Han L. J. Van Der Maas
  • Raoul P. P. P. Grasman
Theoretical and Review Articles

DOI: 10.3758/BF03194023

Cite this article as:
Wagenmakers, EJ., Van Der Maas, H.L.J. & Grasman, R.P.P.P. Psychonomic Bulletin & Review (2007) 14: 3. doi:10.3758/BF03194023
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Abstract

The EZ-diffusion model for two-choice response time tasks takes mean response time, the variance of response time, and response accuracy as inputs. The model transforms these data via three simple equations to produce unique values for the quality of information, response conservativeness, and nondecision time. This transformation of observed data in terms of unobserved variables addresses the speed—accuracy trade-off and allows an unambiguous quantification of performance differences in two-choice response time tasks. The EZ-diffusion model can be applied to data-sparse situations to facilitate individual subject analysis. We studied the performance of the EZ-diffusion model in terms of parameter recovery and robustness against misspecification by using Monte Carlo simulations. The EZ model was also applied to a real-world data set.

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Copyright information

© Psychonomic Society, Inc. 2007

Authors and Affiliations

  • Eric-Jan Wagenmakers
    • 1
  • Han L. J. Van Der Maas
    • 1
  • Raoul P. P. P. Grasman
    • 1
  1. 1.Department of PsychologyUniversity of AmsterdamAmsterdamThe Netherlands