The present study contrasts the validity of a design based on the application of guided lessons plans, the teaching-learning process through' tutorials, and case analyses as means of intruction for students of secondary education. The objective of this study can be categorized as an application of Behavior Principles in the area of Educational Psychology and consists of an attempt to prove the following hypothesis: If a group of secondary school students are submitted to a self instructional technique-with group dynamics following programmed guides, greater efficiency is obtained in concept learning than with the application of traditional 0 conventional methodology. Upon analysis of results it was established that at the begining there were no significant differences in the achievement of the experimental and control groups, where as, after the experimental educational treatment, such differences did exist. From the theorical point of view the article attempts to present a logical sequence for the scientific process. The particularity of the psychologist's activity in underlined in this process, in conclusion, the elaboration of a science within its own operations in conditioned by the historical dimension of the investigator.