What does "Non-Inferiority Margin" mean?

Definition of Non-Inferiority Margin in the context of A/B testing (online controlled experiments).

What is a Non-Inferiority Margin?

A non-inferiority margin is such a difference m that we would be happy implementing a tested treatment if we are to be able to rule out outcomes below -m (negative and smaller in magnitude than m) with our desired significance threshold.

The non-inferiority margin should not be chosen lightly: it should be informed by as objective criteria as possible and it should be communicated to all stakeholders before the A/B test begins.

Like this glossary entry? For an in-depth and comprehensive reading on A/B testing stats, check out the book "Statistical Methods in Online A/B Testing" by the author of this glossary, Georgi Georgiev.

Articles on Non-Inferiority Margin

The Case for Non-Inferiority A/B Tests
blog.analytics-toolkit.com

Related A/B Testing terms

Non-Inferiority Test

See this in action

A/B Testing CalculatorA/B Testing Calculator Statistical Significance CalculatorStatistical Significance Calculator Sample Size CalculatorSample Size Calculator

About the author

Georgi Z. Georgiev

Georgi has over twenty years of experience in online marketing, web analytics, statistics, and design of business experiments.

Author of the book "Statistical Methods in Online A/B Testing", white papers on statistical analysis of A/B tests, and a speaker, he has been distinguished as a winner in the Data & Analytics category of the 2024 Experimentation Thought Leadership Awards.

Purchase Statistical Methods in Online A/B Testing

Statistical Methods in Online A/B Testing

Take your A/B testing program to the next level with the most comprehensive book on user testing statistics in e-commerce.

Learn more

Glossary index by letter

Select a letter to see all A/B testing terms starting with that letter or visit the Glossary homepage to see all.