- noun the hypothesis that something has no effect, as that there is no relationship between income and savings. Comparing this hypothesis with data, calculations can be made to see what exactly the relationship is.
- (written as Null Hypothesis)The prediction that there is no 'effect' or that the theory being tested is not 'true'. In other words, the presumption is that the prediction, theory, etc. in question needs empirical support before it can be accepted even provisionally. The idea is to try to refute the theory; only if one fails does one's acceptance of it begin to be justified. But note that 'has not been refuted' is not an equivalent statement to 'is true', though it is about as far as scientific method can take one towards 'truth'.