Significant questions are addressed in an extensive discussion of the differences between qualitative and quantitative concepts and measurement strategies in the physical sciences. Also included is a discussion of number-generating activities often grouped in the social sciences under the term of measurement. Implications for the redirection of evaluation practice are considered. Specifically, Part I of the report distinguishes between the different types of concepts and the data associated with them. One conclusion is that the initial understanding of a phenomenon must be through qualitative concepts, and from them quantitative concepts may evolve. Part II examines various ways in which numbers are assigned; concluding that neither assignment nor measurement is synonymous with quantification. Part III examines the history of both the qualitative and quantitative in the physical sciences, and the implications for evaluation. The main idea of Part III is that much qualitative work has been prerequisite to fruitful quantification in the physical sciences. Because evaluation draws on the social sciences, which are in early developmental stages, quantification in evaluation may not be as fruitful as qualitative methodology. (Author/GK)