Purpose (of an evaluation study)
The objectives of an evaluation (e.g., to judge the relative merits of competing textbooks, or to monitor and report on how well a project plan is implemented) and the intended use of its reports (e.g., to help teachers choose a textbook or to help a school district carry out a special project).
Yarbrough, D. B., Shulha, L. M., Hopson, R. K., and Caruthers, F. A. (2011). The program evaluation standards: A guide for evaluators and evaluation users (3rd ed.). Thousand Oaks, CA: Sage.