Mixed methode

Mixed methode
Though regression-discontinuity is strong in internal validity and can parallel other non-equivalent designs in terms of validity threats, interpretation of results might be difficult. Outcomes might be the result of combined effects of factors (e.g. better training of teachers, improvement in school facilities) that are not exactly related to the program per se. Depending on the statistical results, it might also be difficult to assess the efficacy of the program. Adding qualitative flesh to the quantitative bones is a good strategy to overcoming some of these problems.

Among the purposes for mixed-method evaluation design, Green et al. (1989) highlight five major ones that might enhance the evaluation as follows:

Triangulation. tests the consistency of findings obtained through different instruments. In the case study, triangulation will increase chances to control, or at least assess, some of the threats or multiple causes influencing our results.

Complementarity clarifies and illustrates results from one method with the use of another method. In our case, in-class observation will add information about the learning process and will qualify the scores and statistics.

Development results from one method shape subsequent methods or steps in the research process. In our case, partial results from the preprogram measures might suggest that other assessments should be incorporated.

Initiation stimulates new research questions or challenges results obtained through one method. In our case, in-depth interviews with teachers and principals will provide new insights on how the program has been perceived and valued across sites.

Expansion provides richness and detail to the study exploring specific features of each method. In our case, integration of procedures mentioned above will expand the breadth of the study and likely enlighten the more general debate on social change, social justice, and equity in Brazil and the role of the public and private sector in this process.