13 Facts About Null hypothesis

The null hypothesis is that the observed difference is due to chance alone.

Usually, the null hypothesis is a statement of 'no effect' or 'no difference'.

Stronger null hypothesis is that the two samples are drawn from the same population, such that the variances and shapes of the distributions are equal.

One-tailed hypothesis is an inexact hypothesis in which the value of a parameter is specified as being either:.

Null hypothesis is a default hypothesis that a quantity to be measured is zero.

Testing the null hypothesis is a central task in statistical hypothesis testing in the modern practice of science.

Concept of a null hypothesis is used differently in two approaches to statistical inference.

The null hypothesis assumes no relationship between variables in the population from which the sample is selected.

Rejection of the null hypothesis is not necessarily the real goal of a significance tester.

Potential null hypothesis implying a one-tail test is "this coin is not biased toward heads".

The outcomes that would tend to refuse this null hypothesis are those with a large number of heads or a large number of tails, and our experiment with 5 heads would seem to belong to this class.

Therefore, the two-tailed null hypothesis will be preserved in this case, not supporting the conclusion reached with the single-tailed null hypothesis, that the coin is biased towards heads.

Fisher said, "the null hypothesis must be exact, that is free of vagueness and ambiguity, because it must supply the basis of the 'problem of distribution, ' of which the test of significance is the solution", implying a more restrictive domain for H0.