A hypothesis (plural hypotheses) is a proposed explanation for a phenomenon. For a hypothesis to be a scientific hypothesis, the scientific method requires that one can test it. Scientists generally base scientific hypotheses on previous observations that cannot satisfactorily be explained with the available scientific theories. Even though the words "hypothesis" and "theory" are often used synonymously, a scientific hypothesis is not the same as a scientific theory. A scientific hypothesis is a proposed explanation of a phenomenon which still has to be rigorously tested. In contrast, a scientific theory has undergone extensive testing and is generally accepted to be the accurate explanation behind an observation. A working hypothesis is a provisionally accepted hypothesis proposed for further research.

A different meaning of the term hypothesis is used in formal logic, to denote the antecedent of a proposition; thus in the proposition "If P, then Qs (or antecedent); Q can be called a consequent. P is the assumption in a (possibly counterfactual) What If question.

The adjective hypothetical, meaning "having the nature of a hypothesis", or "being assumed to exist as an immediate consequence of a hypothesis", can refer to any of these meanings of the term "hypothesis".

Read more about Hypothesis:  Uses, Scientific Hypothesis, Working Hypothesis, Hypotheses, Concepts and Measurement, See Also

Other articles related to "hypothesis":

Descriptive Knowledge - Knowledge in Various Disciplines - Knowledge in Science and Engineering
... A scientist then picks a question of interest, and based on previous knowledge, develops a hypothesis ... designs a controlled experiment which will allow him to test the hypothesis against the real world ... He then makes predictions about the outcome of the test, based on the hypothesis ...
PANDAS - Proposed Mechanism
... The PANDAS diagnosis and the hypothesis that symptoms in this subgroup of patients are caused by infection are controversial ... Researchers are pursuing the hypothesis that the mechanism is similar to that of rheumatic fever, an autoimmune disorder triggered by streptococcal ... The molecular mimicry hypothesis is a proposed mechanism for PANDAS this hypothesis is that antigens on the cell wall of the streptococcal bacteria are similar in some way to the proteins of ...
Hypotheses For The Evolution of Schreckstoff
... The first hypothesis is that the evolution of schreckstoff has been driven by kin selection (Smith 1992) ... Support for this hypothesis would include evidence that individuals live in groups of closely related kin and that the release of chemical alarm signals increases the likelihood that related ... The second hypothesis, predator attraction, suggests that the release of schreckstoff may attract additional predators which will interfere with the predation event, increasing the likelihood that the prey will ...
Eutherian Fetoembryonic Defense System (eu-FEDS) Hypothesis - Hypothesis
... The basic premise of the eu-FEDS hypothesis is that both soluble and cell surface associated glycoproteins, present in the reproductive system and expressed on gametes, suppress any potential immune responses, and ...
Directed Mutagenesis - Recent Studies
... The hypothesis of directed mutagenesis was first proposed in 1988 by John Cairns, of Harvard University who was studying Escherichia coli that lacked the ability to metabolize lactose ... Later support for this hypothesis came from Susan Rosenberg, then at the University of Alberta, who found that an enzyme involved in DNA recombinational repair, recBCD, was ... The directed mutagenesis hypothesis was challenged in 2002, when John Roth and colleagues showed that the phenomenon was due to general hypermutability due to ...

Famous quotes containing the word hypothesis:

    The great tragedy of science—the slaying of a beautiful hypothesis by an ugly fact.
    Thomas Henry Huxley (1825–95)

    On pragmatistic principles, if the hypothesis of God works satisfactorily in the widest sense of the word, it is true.
    William James (1842–1910)

    It is a good morning exercise for a research scientist to discard a pet hypothesis every day before breakfast. It keeps him young.
    Konrad Lorenz (1903–1989)