The null hypothesis (H0) is a statement that suggests there is no effect, no difference, or no relationship between the variables being studied in a statistical test. It serves as the default position that researchers aim to test, and the goal of hypothesis testing is to determine whether there is enough evidence to reject the null hypothesis in favor of an alternative hypothesis (H1) that suggests an effect or difference exists. The null hypothesis is typically formulated in a way that reflects a status quo or baseline assumption, and it provides a framework for assessing the significance of observed data.

The null hypothesis is a statement of "no effect" or "no difference." It is the default assumption that there is no significant relationship or difference between variables. When conducting a statistical test, the goal is to gather evidence to either reject or fail to reject this null hypothesis.