be operationalized as miles, whereas kilometers would be used in Europe. Operationalization is part of the empirical research process. Take for example an empirical research question: Does job satisfaction influence job turnover? Both job satisfaction and job turnover need to be measured. The concepts and their relationship are important — operationalization occurs within a larger framework of concepts. When there is a large empirical research question or purpose the conceptual framework that organizes the response to the question must be operationalized before the data collection can begin. If a scholar constructs a questionnaire based on a conceptual framework, they have operationalized the framework. Most serious empirical research should involve operationalization that is transparent and linked to a conceptual framework. To use an oversimplified example, the hypothesis Job satisfaction reduces job turnover is one way to connect (or frame) two concepts – job satisfaction and job turnover. The process of moving from the idea job satisfaction to the set of questionnaire items that form a job satisfaction scale is operationalization. For example, it is possible to measure job satisfaction using only two simple questions: 1) "All in all, I am satisfied with my job"; 2) "In general, I like my job." Operationalization uses a different logic when testing a formal (quantitative) hypothesis and testing working hypothesis (qualitative). For formal hypotheses the concepts are represented empirically (or operationalized) as numeric variables and tested using inferential statistics. Working hypotheses (particularly in the social and administrative sciences), on the other hand, are tested through evidence collection and the assessment of the evidence. The evidence is generally collected within the context of a case study. The researcher asks - Is the evidence sufficient to 'support' the working hypothesis? Formal operationalization would specify the kinds of evidence needed to support the hypothesis as well as evidence which would "fail" to support it. Robert Yin recommends developing a case study protocol as a way to specify the kinds of evidence needed during the data collection phases. He identifies six sources of evidence 1) documentation; 2) archival records; 3) interviews; 4) direct observations; 5) participant observation and 6) physical or cultural artifacts. In the field of public administration, Shields and Tajalli (2006) have identified five kinds of conceptual frameworks (working hypothesis, descriptive categories, practical ideal type, operations research, and formal hypothesis). They explain and illustrate how each of these conceptual frameworks can be operationalized. They also show how