Hypothesis testing is one of the most important concepts in Statistics.
This is how we decide if:

• Effects actually occurred.
• Treatments have effects.
• Groups differ from each other.
• One variable predicts another.

There are complicated definitions and descriptions of the process. They may confuse you. The logic will seem backward.

The idea process of hypothesis testing if written in plain English, is simple. We will write it out before introducing complex terms.