Table 1.

Meaning of null hypothesis in hypothesis testing

Test methods		Means
Brown-Forsythe test	H0	The sample variances are equal across different groups
	H1	The sample variances are not equal across different groups
Mann–Whitney U test	H0	Two independent sample groups come from the same distribution, and there is no significant difference between the two sets of data
	H1	Two independent sample groups come from different distributions, and there is a significant difference between the two sets of data