acceptance region
From Glossary of Meteorology
A range of values of a sample statistic used to test a hypothesis.
In the testing procedure, the sampling region is divided into an acceptance region and a rejection region. If the sample statistic lies within the acceptance region, the null hypothesis (a hypothesis usually based on conventional theory) is provisionally accepted. If the sample statistic lies in the rejection region, the alternative hypothesis that contradicts the null hypothesis is accepted.
See significance test.