ABSTRACT
The process of selecting observable phenomena to represent abstract concepts is known as operationalization, and the specification of steps to take in making observations is called instrumentation because it involves the development of measuring "instruments." The chapter discusses the problems people may encounter in attempting to operationalize and measure concepts. It focuses on answering research questions using quantitative data rather than employing qualitative methods. The challenges in research are to devise ways of getting from the abstract level of research questions to some concrete observation that will allow answering them. Two primary types of validity are associated with empirical research: internal and external. Internal validity involves accurate measurement of people theoretical concepts. External validity pertains to the generalizability of people results. Factors That Threaten External Validity: interaction effects of testing, interaction of selection and experimental treatment, reactive effects of experimental arrangements, multiple-treatment interference, irrelevant responsiveness of measures, and irrelevant replicability of treatments..
