If you want to understand ‘evaluation research’, a good way to begin is by reading Ranjit Kumar (2010, ch.18). His model for the concept of evaluation looks like this:
The concept of evaluation (Kumar, 2010, p.325)
Kumar suggests that evaluation can be approached from two perspectives (p.328): “the focus of the evaluation; and the philosophical base that underpins an evaluation“. The types of evaluation that arise from each perspective are shown in the figure below. He emphasises that the perspectives are not mutually exclusive, explaining this with the example of a study which determines the impact of a programme by asking what its clients perceive its effects to have been on them. This study could be classified as an impact / outcome evaluation from the ‘focus of the evalution’ perspective or, equally, as a client-centred evaluation from the ‘philosophical’ perspective.
From the perspective of the focus of the evaluation, there are many designs or methods of evaluation. For example in an impact assessment evaluation Kumar identifies (p.338) the following commonly used designs:
- after-only design;
- before-and-after design;
- experimental control design;
- comparative study design;
- reflexive control design;
- interrupted time-series design (see model below);
- replicated cross-sectional design
From a philosophical perspective, Kumar argues (p.342) that “there are no specific models or methods of evaluation. You use the same methods and models [as for the other perspective] but the required information is gathered from different people or aspects …”
Kumar provides an informative overview. For greater detail and a better appreciation of these perspectives he recommends Stufflebeam & Shinkfield (1985).
KUMAR, R. 2010. Research methodology: A step-by-step guide for beginners, Sage Publications Ltd.
STUFFLEBEAM, D. L. & SHINKFIELD, A. J. 1985. Systematic evaluation: A self-instructional guide to theory and practice, Kluwer-Nijhoff Boston.