Statistics is considered a basic instrument for information analysis. Therefore, it is teaching in Psychology is of the utmost importance. However, there are difficulties in the interpretation of statistical concepts by university students. Consequently, the present study seeks to use the Psychometrics Group Instrument to compare scores obtained by a group of Psychology students attending a teaching program based on the Merrill’s instructional design concerning what was found in three previous studies, and to analyse the effects produced by the teaching program for the improvement of the interpretation of statistical concepts. The participants were Psychology undergraduate students from a public university in Lima, Peru. The results indicated that the sample presents a low knowledge level in some statistical concepts, before the teaching program, similar to the three comparison investigations. On the other hand, the teaching program generated an improvement in the interpretation of statistical concepts presented in it. Based on the evidence found on Merrill’s instructional design, it is recommended to proof each of its principles in the development of learning sessions on Statistics in social, health and behavioural sciences careers. All materials, code and data are publicly accessible via the Open Science Framework (OSF) at https://osf.io/pxbcs/.