Marketing Research and Insight Glossary

Definitions, common uses and explanations of 1,500+ key market research terms and phrases.

What is the Rejection region?

Content Type:
Glossary
Share Print

Rejection region Definition

Those values of the test statistic that would lead to the rejection of the null hypothesis.

The rejection region is the range of values for a test statistic that leads to the rejection of the null hypothesis in hypothesis testing. It is determined by the chosen significance level (alpha), typically 0.05 or 0.01, and indicates where observed results are statistically unlikely under the null.

Who relies on understanding the rejection region in market research?

Statisticians, quantitative researchers, data analysts and academic researchers rely on the rejection region when conducting hypothesis tests to evaluate research outcomes.

What are the key aspects of a rejection region in market research?

  • Defined by the significance level (alpha).
  • Located in the tails of the probability distribution.
  • Associated with Type I error (false positive).
  • Used in t-tests, z-tests, ANOVA and other inferential tests.
  • Reflects decision rules for statistical significance.

Why is the rejection region important in market research?

It helps researchers make objective decisions about whether observed differences or effects are likely due to chance or reflect real phenomena. This supports rigorous data interpretation and evidence-based recommendations.

How do market researchers use the rejection region?

Researchers use it to evaluate p-values from statistical tests. If the p-value falls within the rejection region, they reject the null hypothesis and conclude that the observed effect is statistically significant, informing next steps in strategy or reporting.