Different definitions of and/or approaches to self-esteem |
Lack of a theoretical framework in some studies |
Different self-esteem assessment scales |
Arbitrary (and differing) thresholds applied to the results of the scales |
Inconsistencies between the theoretical framework and the scale used in some studies |
Different study populations [40] |
Different measurement schedules [8,41,42] |
Design often cross-sectional or post-interventional |
Losses to follow-up due to attrition [43] |
Impact of the vocational character of the training [44] |
Few explanations of the phenomenon (process and reasons for changes in self-esteem, or interaction mechanisms) |