1. Example: the Justice system: A person is accused of murder and is on trial. How should the error table look like?

2. Null hypothesis D E C I S I O N Defendant is innocent Defendant is not innocent Type I Error Defendant is found NOT innocent Correct Decision Correct Decision Acquit Convict Type II Error Defendant is found innocent

3. Are the consequences of Type I error more severe or Type II error consequences?

4. DECISIONDECISION Reject H 0 Do Not reject H 0 Null hypothesis H 0 trueH 0 false Type I Error H 0 is true but it is rejected Correct Decision Correct Decision Type II Error H 0 is false but is NOT rejected.

5. Drug testing Welfare recipients

6. DECISIONDECISION Null hypothesis The recipient is drug free The recipient is NOT drug free Test + Correct Decision Test - Type I error Type II error

7. Example in Education The state of Georgia is considering spending $350 million on a computerized mathematics curriculum that for grades 3 – 10. They pilot the program with 250 students in grades 5 and 6 whose end- of-course test scores are compared to the state average score of 150.

8. DECISIONDECISION Null hypothesis

9. DECISIONDECISION

10. Example in Medicine Pharmaceutical researchers are testing a new drug for acne. Severity of acne is rated on a scale of 1 – 7, 7 being “worst.” Side effects for the new drug may include vomiting, upset stomach, mild fever and/or hyperactivity. Their sample size is 80, with participants randomly assigned to a control group (n = 40) and treatment group (n = 40).