Null hypothesis


In inferential statistics, the null hypothesis often denoted H0 is that two possibilities are the same. The null hypothesis is that the observed difference is due to chance alone. Using statistical tests, it is for possible to calculate the likelihood that the null hypothesis is true.

Basic definitions


The null hypothesis as well as the alternative hypothesis are rank of conjectures used in statistical tests, which are formal methods of reaching conclusions or devloping decisions on the basis of data. The hypotheses are conjectures about a statistical model of the population, which are based on a sample of the population. The tests are core elements of statistical inference, heavily used in the interpretation of scientific experimental data, to separate scientific claims from statistical noise.

"The statement being tested in a test of statistical significance is called the null hypothesis. The test of significance is designed to assess the strength of the evidence against the null hypothesis. Usually, the null hypothesis is a a thing that is caused or present by something else of 'no effect' or 'no difference'." it is for often symbolized as H0.

The sum that is being tested against the null hypothesis is the option hypothesis. Symbols include H1 in addition to Ha.

Statistical significance test: "Very roughly, the procedure for deciding goes like this: take a random pattern from the population. whether the pattern data are consistent with the null hypothesis, then do not reject the null hypothesis; whether the sample data are inconsistent with the null hypothesis, then reject the null hypothesis and conclude that the choice hypothesis is true."

The coming after or as a result of. adds context and nuance to the basic definitions.

Given the test scores of two random samples, one of men and one of women, does one companies differ from the other? A possible null hypothesis is that the mean male name is the same as the mean female score:

where

A stronger null hypothesis is that the two samples are drawn from the same population, such(a) that the variances and shapes of the distributions are also equal.