Table 1.

Setting the scope of the search: inclusion and exclusion criteria

Inclusion criteria	Exclusion criteria
1. Studies/reviews/meta-analysis focusing on the encouragement of undergraduate students' intrinsic motivation.	1. Studies not empirical in nature like view- points, editorials, papers expressing opinion and books.
2. Studies/reviews/meta-analysis within Health Professions Education or General Higher Education.	2. Studies on populations other than undergraduate students or teachers in health professions education or General Higher Education.
3. Quantitative research studies with well-formulated definitions, operationalization of concepts and analysis of data.	3. Studies not referring to motivation in higher education.
4. Qualitative research studies with well-defined concepts, reliable methods, well-reasoned conclusions and analysis.	4. Studies focusing on motivation in education for specific issues not regarding teaching.
5. Articles available in English and Spanish Language, published from year 1993.	5. Studies focused on instrument construction/validation.