Our past experience creates a perceptual bias (remember the role of values in sociology) Objectivity is achieved by testing theories against systematically collected data and by leaving research open to public scrutiny. Theory is a tentative explanation of social phenomenon. Aristotle: concept is a thought about the essence of that whereof we are. Operationalization is the process of translating theories and concepts (abstract ideas) into hypotheses and variables (ideas about concrete, observable phenomena) It is the link between theory and research. Research: collecting and analyzing observations of relevant phenomena. Concepts cannot be observed directly, but their indicators/measures can. Variable is an observable phenomenon (an indicator/measure of a concept) that can assume different values. Hypotheses is a testable claim (expectation) about an observable phenomenon based on theory. It is a link between a specific theory and specific research. A hypothesis usually expresses a relationship of variables.