In hypothesis testing, what does the term "null hypothesis" mean?

The term "null hypothesis" refers to a fundamental concept in statistical hypothesis testing that serves as a starting point for analysis. It is typically denoted as H0 and asserts that there is no effect, no difference, or no relationship in the population being studied. This assertion represents a baseline or default position that researchers aim to test against.

In hypothesis testing, the null hypothesis is critical because it allows researchers to use statistical methods to determine whether there is enough evidence to reject this assumption. If the data show significant evidence against the null hypothesis, researchers may consider supporting an alternative hypothesis, which asserts that there is indeed an effect or difference.

The null hypothesis plays a pivotal role in the scientific method by framing the research question in a way that scientific testing can evaluate potential outcomes. Its importance lies in its provision of a clear criterion for statistical decision-making, guiding researchers in drawing conclusions based on empirical evidence.