The present study could not succeed without the cooperation of the doctoral students of the University Hassan II
Mohammedia in Casablanca. The author wishes to thank the president of the university, the deans of the faculties,
and the subjects of our study for their valuable help. We would also like to express sincere gratitude to the directors
of the doctoral studies centres. Finally, the author wishes to thank the Procedia - Social and Behavioural Journal.
Aspects of this research were presented by the first named author at the 5th World Conference on Educational
Sciences, Sapienza University, Italy, 2013.