This paper presents a theoretical and practical methodology to improve the teaching-learning process of Mechanics of Materials. The methodology was used during six academic periods in the Civil Engineering Department of Universidad de Ibague. It comprises three stages: observation of the phenomena, study of constitutive equations, and experimentation. In the first stage, students observe phenomena related to the topics of study, in the second stage, professor and students deepen into the theoretical conceptualization of the observed phenomena, deduce the mathematical equations of practical use for the phenomena, and solve implementation problems. In the third stage, students build mathematical and physical models as a course project. The methodology was implemented as an attempt to reduce the high levels of desertion and failure, and to contrast the traditional teaching methodology where the lecturer teacher is the center of the learning process. With the proposed methodology desertion decreased and students´ performance increased.