RESEARCH ARTICLE A domain-specific visual language for modeling metacognition in intelligent systems Manuel F. Caro a,* , Darsana P. Josyula b , Jovani A. Jime ´nez c , Catriona M. Kennedy d , Michael T. Cox e a Grupo de Investigacio ´n en Informa´tica y Computacio ´n Cognitiva, Departamento de Informa´tica Educativa, Universidad de Co ´rdoba, Monterı ´a, COR, Colombia b Department of Computer Science, Bowie State University, Bowie, MD, USA c Departamento de Ciencias de la Computacio ´n y la Decisio ´n, Universidad Nacional de Colombia, Medellı ´n, ANT, Colombia d School of Computer Science, University of Manchester, Manchester, United Kingdom e Wright State Research Institute, Beavercreek, OH 45431, USA Received 5 June 2015; received in revised form 28 June 2015; accepted 28 June 2015 KEYWORDS Metacognition; Domain-specific visual language; Intelligent system; Modeling tool; MOF Abstract Metacognition has been used in artificial intelligence to increase the level of autonomy of intel- ligent systems. However the design of systems with metacognitive capabilities is a difficult task due to the number and complexity of processes involved. This paper presents a domain-specific visual language specifically developed for modeling metacognition in intelligent systems called M++. In M++ the specifications of the cognitive level (object-level) and metacognitive level (meta-level) are supported in a metamodel configured according to the standard Meta-Object Facility (MOF) of Model-Driven Architecture (MDA) methodology. M++ allows the generation of metacognitive diagrams in a visual editor named MetaThink. A validation process was conducted to ensure the reliability of M++ in terms of quality of the notation and consis- tency of generated models. The validation was performed using two techniques: (i) empirical study and (ii) model tracing. The results given in the experimental study demonstrate that M++ is a useful notation for the process of modeling metacognitive components in intelligent systems. Metacognitive models generated from the validation process using the Tracing technique were consistent with the MOF-based metamodel. M++ contribute to cognitive architecture http://dx.doi.org/10.1016/j.bica.2015.06.004 2212-683X/ª 2015 Elsevier B.V. All rights reserved. * Corresponding author. E-mail addresses: mfcarop@unal.edu.co (M.F. Caro), darsana@cs.umd.edu (D.P. Josyula), jajimen1@unal.edu.co (J.A. Jime ´nez), catriona.kennedy@manchester.ac.uk (C.M. Kennedy), michael.cox@wright.edu (M.T. Cox). Biologically Inspired Cognitive Architectures (2015) 13, 75– 90 Available at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/bica