#### To whom is the researcher similar in hypothesis testing: the defense attorney or the prosecuting attorney? Why?

The researcher is similar to the *prosecuting attorney* in the sense that the researcher brings the null hypothesis “to trial” when she believes there is a probability of strong evidence against the null.

- Just as the prosecutor usually believes that the person on trial is not innocent, the researcher usually believes that the null hypothesis is not true.
- In the court system, the jury must assume (by law) that the person is innocent until the evidence calls this assumption into question; analogously, in hypothesis testing the researcher must assume (to use hypothesis testing) that the null hypothesis is true until the evidence calls this assumption into question.

The world aournd us is complex enough and full of uncertainty. Onlyobserving the data can not tell us if a pattern or relationship exists, or if it is just due to random chance. Therefore, we need hypthesis testing procedure that provides us a systematic method to analyze the sample data and draw conclusions (or make wise decisions) about a larger population, with a clear understanding of the likelihood of being wrong.

In conclusion, like statistical estimation, the statistical hypothesis testing is a cornerstone of statistical analysis. It provides a way to move beyond simply observing data and allows us to draw meaningful inferences about populations, evaluate claims, and make informed decisions in the face of uncertainty.