<P> In recent years, philosophers of science have tried to integrate the various approaches to evaluating hypotheses, and the scientific method in general, to form a more complete system that integrates the individual concerns of each approach . Notably, Imre Lakatos and Paul Feyerabend, Karl Popper's colleague and student, respectively, have produced novel attempts at such a synthesis . </P> <P> Concepts in Hempel's deductive - nomological model play a key role in the development and testing of hypotheses . Most formal hypotheses connect concepts by specifying the expected relationships between propositions . When a set of hypotheses are grouped together they become a type of conceptual framework . When a conceptual framework is complex and incorporates causality or explanation it is generally referred to as a theory . According to noted philosopher of science Carl Gustav Hempel "An adequate empirical interpretation turns a theoretical system into a testable theory: The hypothesis whose constituent terms have been interpreted become capable of test by reference to observable phenomena . Frequently the interpreted hypothesis will be derivative hypotheses of the theory; but their confirmation or disconfirmation by empirical data will then immediately strengthen or weaken also the primitive hypotheses from which they were derived ." </P> <P> Hempel provides a useful metaphor that describes the relationship between a conceptual framework and the framework as it is observed and perhaps tested (interpreted framework). "The whole system floats, as it were, above the plane of observation and is anchored to it by rules of interpretation . These might be viewed as strings which are not part of the network but link certain points of the latter with specific places in the plane of observation . By virtue of those interpretative connections, the network can function as a scientific theory ." Hypotheses with concepts anchored in the plane of observation are ready to be tested . In "actual scientific practice the process of framing a theoretical structure and of interpreting it are not always sharply separated, since the intended interpretation usually guides the construction of the theoretician ." It is, however, "possible and indeed desirable, for the purposes of logical clarification, to separate the two steps conceptually ." </P> <P> When a possible correlation or similar relation between phenomena is investigated, such as whether a proposed remedy is effective in treating a disease, the hypothesis that a relation exists cannot be examined the same way one might examine a proposed new law of nature . In such an investigation, if the tested remedy shows no effect in a few cases, these do not necessarily falsify the hypothesis . Instead, statistical tests are used to determine how likely it is that the overall effect would be observed if the hypothesized relation does not exist . If that likelihood is sufficiently small (e.g., less than 1%), the existence of a relation may be assumed . Otherwise, any observed effect may be due to pure chance . </P>

What functions does hypothesis serve in a research study