2. Because each observation must be independent, we have to assign each participant individually and take steps to be sure that participant’s don’t influence each other’s responses.
3. Because we want power, we want to have at least 30 (preferably 120) participants.
4. Because we cannot prove the null hypothesis, our hypothesis must be that a treatment has an effect.
5. Because we would like to use the t test, we want to choose a measure that will give us interval data.