Despite the formal, non-formal and informal training opportunities offered by MOOCs, they show low completion rates due to both personal factors of the participants and the instructional design of the courses. Empirical research has shown that good instructional design can help increase learners' motivation, helping them achieve high performance by completing the program. To determine to which extent the quality instructional material, which is the result of a good instructional design, contributes to their motivation and high rates of completion of the courses, we created an eight (8) week MOOC program on "Violence and bullying in schools", following the instructional design model "Systems Approach Model". The motivation of the learners from the instructional material was measured using the Instructional Material Motivation Survey (IMMS) tool and showed that all the learners were highly motivated both as a whole and in every factor of the ARCS model (Attention, Relevance, Confidence, Satisfaction) contributing to very high completion rates, as from the 1309 learners who started the program, 1050 completed it (80.2%). Considering the results of our research, we, finally, suggest some points that can be taken into account when designing similar programs.