Attempting fonnally to evaluate something involves the evaluator coming
to grips with a number of abstract concepts such as value, merit, worth,
growth, criteria, standards, objectives, needs, nonns, client, audience,
validity, reliability, objectivity, practical significance,
accountability, improvement, process, pro- duct, fonnative, summative,
costs, impact, infonnation, credibility, and - of course - with the tenn
evaluation itself. To communicate with colleagues and clients,
evaluators need to clarify what they mean when they use such tenns to
denote important concepts central to their work. Moreover, evaluators
need to integrate these concepts and their meanings into a coherent
framework that guides all aspects of their work. If evaluation is to lay
claim to the mantle of a profession, then these conceptualizations of
evaluation must lead to the conduct of defensible evaluations. The
conceptualization of evaluation can never be a one-time activity nor can
any conceptualization be static. Conceptualizations that guide
evaluation work must keep pace with the growth of theory and practice in
the field. Further, the design and conduct of any particular study
involves a good deal of localized conceptualization.