1. Chapter 11 11.3 Use and Abuse of Tests

2. Choosing a Level of Significance How plausible is H 0 ? What are the consequences of rejecting H 0 ? There is no sharp border between “statistically significant” and “statistically insignificant,” only increasingly strong evidence as the P-value decreases.

3. Example 11.13 Statistical Significance and Practical Importance Wound Healing Time Page 717

4. Cautions Statistical significance is not the same thing as practical importance. The foolish user of statistics who feeds the data to a calculator or computer without exploratory analysis will often be embarrassed.

5. Don’t Ignore Lack of Significance Reducing HIV transmission; Example 11.14 Psychology journals; Example 11.15 When planning a study, verify that the test you plan to use has a high probability of detecting an effect of the size you hope to find.

6. Statistical Inference Is Not Valid for All Sets of Data Does music increase worker productivity; Example 11.16 If we analyze data that do not arise from randomized samples or experiments, we must have confidence in the use of probability to describe the data.

7. Beware of Multiple Analyses Cell phones and brain cancer; Example 11.17

8. Assignment Page 721; 11.43 – 11.48