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close this bookNutrition education for the public. Discussion papers of the FAO Expert Consultation (Rome, Italy, 18-22 September 1995) - FAO Food and Nutrition Paper 62 - (1997)
close this folderEvaluation of nutrition education programmes: Implications for programme planners and evaluators
View the document(introduction...)
View the documentIntroduction
View the documentBackground
View the documentThe purpose of evaluation
View the documentDeveloping an evaluation system
View the documentQualitative versus quantitative methodologies
View the documentMeasuring efficiency
View the documentSkills needed in evaluation
View the documentConcluding remarks
View the documentRecommendations
View the documentReferences

Qualitative versus quantitative methodologies

The discussion so far has basically focused on quantitative evaluation. While impact or outcome evaluation is often quantitative, process evaluation and monitoring also use qualitative information. The relative advantages and disadvantages have been debated extensively in the evaluation literature (Rossi & Freeman, 1993). In the 1970s and early 1980s quantitative evaluation, was heavily criticised (Cook & Reichardt, 1979; Patton, 1980; Lincoln & Guba, 1985). Patton (1978) writes:

“Evaluation research is dominated by the largely unquestioned, natural science paradigm of hypothetico-deductive methodology. This dominant paradigm assumes quantitative measurement, experimental design, and multivariate, parametric statistical analysis to be the epitome of “good” science... By way of contrast, the alternative to the dominant hypothetico-deductive paradigm is derived from the tradition of anthropological field studies. Using the techniques of in-depth, open-ended interviewing and personal observation, the alternative paradigm relies on qualitative data, holistic analysis, and detailed description derived from close contact with the targets of study. The hypothetico-deductive, natural science paradigm aims at prediction of social phenomena; the holistic-inductive, anthropological paradigm aims at understanding of social phenomena. “

Patton agrees, however, that from a utilisation-focused perspective on evaluation, neither of these paradigms is intrinsically better than the other. They represent alternatives from which the evaluator can choose (Patton, 1978). Today the hypothetico-deductive paradigm is not seen in such a negative light. A statistical analysis is not limited to parametric analysis and most evaluators will collect both qualitative as well as quantitative information. As pointed out by Rossi and Freeman (1993), qualitative evaluators often tend to be oriented toward making a programme work better by feeding information on the programme to its managers (formative evaluation). In contrast, quantitatively-oriented evaluators view the field as one primarily concerned with impact or outcome evaluation (summative evaluation). The polemics against or for pure qualitative or quantitative evaluation obscure the critical point - namely, that each approach is useful, and the choice of approaches depends on the evaluation question at hand. Rossi and Freeman (1993) point out that qualitative approaches can play critical roles in programme design and are important means of monitoring programmes (process evaluation). In contrast, quantitative approaches are much more appropriate in estimates of net impact, as well as in assessments of the efficiency of programme efforts.

However, qualitative procedures are difficult and expensive to use if the evaluation depends entirely on this. For example, it would be very difficult and expensive (Rossi & Freeman say that it would be virtually impossible) to build on qualitative observation in large-scale surveys.

The critical issue is thus fitting the approach to the purpose of the evaluation. The use of both qualitative and quantitative, and multiple methods9, can strengthen the validity of findings, if results produced by different methods are congruent and/or complement each other10 (see Figure 7).

9 Often referred to as “triangulation” (Green & McClintock, 1985).

10 Congruence here means similarity, consistency, or convergence of results, whereas complementarity refers to one set of results enriching, expanding upon, clarifying, or illustrating the other. Thus, the essence of the triangulation logic is that the methods represent independent assessments of the same phenomenon and contain offsetting kinds of bias and measurement error (Green & McClintock, 1985).

Figure 7: The use of qualitative vs. quantitative methodologies in evaluation

· Both types of methodologies are important

· Qualitative methodologies are useful in monitoring and process evaluation

· Outcome/impact evaluation is often quantitative

· Use of both types of methodologies strengthen validity of findings