A Formal Semantics for the Cognitive Architecture ACT-R

  • Daniel GallEmail author
  • Thom Frühwirth
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 8981)


The cognitive architecture ACT-R is very popular in cognitive sciences. It merges well-investigated results of psychology to a unified model of cognition. This enables researchers to implement and execute domain-specific cognitive models. ACT-R is implemented as a production rule system. Although its underlying psychological theory has been investigated in many psychological experiments, ACT-R lacks a formal definition from a mathematical-computational point of view.

In this paper, we present a formalization of ACT-R’s fundamental concepts including an operational semantics of the core features of its production rule system. The semantics abstracts from technical artifacts of the implementation. Due to its abstract formulation, the semantics is eligible for analysis. To the best of our knowledge, this operational semantics is the first of its kind.

Furthermore, we show a formal translation of ACT-R production rules to Constraint Handling Rules (CHR) and prove soundness and completeness of the translation mechanism according to our operational semantics.


Computational psychology Cognitive systems ACT-R Production rule systems Constraint handling rules Operational semantics 


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Copyright information

© Springer International Publishing Switzerland 2015

Authors and Affiliations

  1. 1.Institute of Software Engineering and Compiler ConstructionUniversity of UlmUlmGermany

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