Editing Biostatistics (section)

=== Mis-specification and robustness checks ===

The main hypothesis being tested (e.g., no association between treatments and outcomes) is often accompanied by other technical assumptions (e.g., about the form of the probability distribution of the outcomes) that are also part of the null hypothesis. When the technical assumptions are violated in practice, then the null may be frequently rejected even if the main hypothesis is true. Such rejections are said to be due to model mis-specification.<ref>{{Cite web|url=https://www.statlect.com/glossary/null-hypothesis|title=Null hypothesis|website=www.statlect.com|access-date=2018-05-08}}</ref> Verifying whether the outcome of a statistical test does not change when the technical assumptions are slightly altered (so-called robustness checks) is the main way of combating mis-specification.