To write a null hypothesis, begin by formulating a research question. Then rephrase that question in a way that assumes no relationship between the variables of interest.

A null hypothesis is a type of statistical hypothesis that proposes that no statistical significance exists in a set of given observations.

To explain observations in science a prediction and a hypothesis are made. Learn how to develop these skills with BBC Bitesize. For students between the ages of 11 and 14.

In his popular series, Andrew Vickers, PhD, discusses the null hypothesis, using surgical infection rates to demonstrate a problem in interpretation.