hypothesis /hy·poth·e·sis/ (hi-poth´ĕ-sis) a supposition that appears to explain a group of phenomena and is advanced as a basis for further investigation.
hypothesis
hypothesis,
hypothesis
alternative hypothesis one that is compared with the null hypothesis in a statistical test.
biogenic amine hypothesis the hypothesis that depression is associated with deficiency of biogenic amines, especially norepinephrine, at functionally important receptor sites in the brain and that elation is associated with excess of such amines.
jelly roll hypothesis a theory explaining the formation of nerve myelin, which states that it consists of several layers of the plasma membrane of a Schwann cell wrapped spirally around the axon in a jelly roll fashion.
lattice hypothesis a theory of the nature of the antigen-antibody reaction which postulates reaction between multivalent antigen and divalent antibody to give an antigen-antibody complex of a lattice-like structure.
Lyon hypothesis the random and fixed inactivation (in the form of sex chromatin) of one X chromosome in mammalian cells at an early stage of embryogenesis, leading to mosaicism of paternal and maternal X chromosomes in the female.
null hypothesis the particular one under investigation, which frequently asserts a lack of effect or of difference.
one gene–one polypeptide chain hypothesis a gene is the DNA sequence that codes for the production of one polypeptide chain. Antibodies are an exception; separate genes for variable and constant regions are rearranged to code for a single polypeptide.
response-to-injury hypothesis one explaining atherogenesis as initiating with some injury to the endothelial cells lining the artery walls, which causes endothelial dysfunction and leads to abnormal cellular interactions and initiation and progression of atherogenesis.
sliding filament hypothesis the stretching of individual muscle fibers raises the number of tension-developing bridges between the sliding contractile protein elements (actin and myosin) and thus augments the force of the next muscle contraction.
Starling's hypothesis the direction and rate of fluid transfer between blood plasma in the capillary and fluid in the tissue spaces depend on the hydrostatic pressure on each side of the capillary wall, on the osmotic pressure of protein in plasma and in tissue fluid, and on the properties of the capillary walls as a filtering membrane.
wobble hypothesis one describing how a specific transfer RNA (tRNA) molecule can translate different codons in a messenger RNA (mRNA) template. It states that the third base of the tRNA anticodon does not have to pair with a complementary codon (as do the first two) but can form base pairs with any of several related codons.
hy·poth·e·sis (h -p th  -ss)n. pl. hy·poth·e·ses (-s  z ) A tentative explanation that accounts for a set of facts and can be tested by further investigation. hy po·theti·cal (hp -th t-kl) adj. |
hypothesis
[hīpoth′isis]
Etymology: Gk, groundwork
(in research) a statement derived from a theory that predicts the relationship among variables representing concepts, constructs, or events. Kinds of hypotheses include causal hypothesis, null hypothesis, and predictive hypothesis.
hypothesis,
n an experimentally testable proposal given as the basis for additional examination.
hypothesis
a supposition that appears to explain a group of phenomena and is assumed as a basis of reasoning and experimentation.
hypothesis testing
a standard practice using statistical methods, usually analytical observational studies, to differentiate between two hypotheses. For example, the user assumes that vaccination against a particular disease reduces the prevalence of the disease, then tests that hypothesis.
hypothesis testing sampling
sampling of material or data for the purpose of testing a hypothesis.
significance
In statistics, an indication that the results of an investigation on a population (e.g. patients) differ from those of another population (e.g. general) by an amount that could not happen by chance alone. This is evaluated by establishing a significance level, that is the probability, called p value, which leads us to reject or accept the null hypothesis Ho (there is no significant difference between two populations and the difference is attributed to chance) and accept or reject the alternative hypothesis H1 that there is a statistically significant difference between two populations. A p value p < 0.05 is often considered significant, but the lower this figure, the stronger the evidence. See randomized controlled trial.
hypothesis
Epidemiology A supposition, arrived at from observation or reflection, that leads to refutable predictions; a conjecture cast in a form that will allow it to be tested and refuted
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