ABSTRACT
The transition from theory to empirical research is called operationalization. In the phase of operationalization, theoretical concepts are translated into entities that can be observed or measured in the real world. This chapter discusses the risks and problems with respect to validity and reliability associated with the different methods. The reliability of a study is a function of the accuracy, and the consistency with which the variables are measured. The way of guarding validity is to ask fellow researchers, methodologists and experts to comment on the chosen operationalization and sampling method. The chapter discusses several sources of interference that can impair the reliability and validity of a study. There are three main sources of interference. First source is caused by the research method or measurement instrument used during both the phases of gathering and processing information. Second source is interference caused by the researcher and third source is interference caused by the units of study.
