What is Null and Alternative hypothesis in statistics and how to write them, explained with simple and easy examples.

Hypothesis testing is the fundamental and the most important concept of statistics used in Six Sigma and data analysis. And the first step of hypothesis testing is forming Null and Alternative hypothesis.

Before we move to write our null hypothesis, let us first understand the need of doing hypothesis testing.

Why do Hypothesis Testing

In the Measure Phase of a DMAIC project, we conduct brain storming exercises with subject matter experts and prepare a list of probable causes.

Similarly, basis initial data analysis we identify certain trends and form assumptions. All these probable causes and assumptions are nothing but our hypothesis in simple language.

Below are the specific reasons why we perform hypothesis testing.