This paper seeks to develop a methodology that will discover, specify and measure students’ abilities and skills in creating concept maps. Because competencies are the key factor in higher education, the paper analyzes the role of concept maps as a tool to diagnose and improve information analysis, synthesis, organization and representation skills and competencies. We propose a methodology that enables these skills to be evaluated by observing, analyzing and measuring the stages involved in creating a concept map: identification of the main and secondary subjects; subject codification by concepts; grading of concepts; and representation of the concepts and their relationships with labels. A case study using action research methodology tests its usefulness on a group of university students of library and information science. The method proposed provides information on the strengths and weaknesses of the students’ skills, thus enabling their training to be improved by means of specific actions.