1. Unit 9 Quiz: Review questions

2. Can you explain your answer?
Use your fingers to indicate your answer: 1=A, 2=B, 3=C, 4=D.
After viewing the question, show me your answer in 15 seconds.
Next, turn to your neighbor and you have one minute to convince him/her that you are right.

3. What is statistical power?
The probability of rejecting the null hypothesis when the null is false.
The probability of detecting a true effect.
1 – beta
All of the above

4. What is effect size?
The distance between the null and the alternate (how far away from zero effect?)
In regression it means how steep the slope is.
The magnitude of the effect of the independent variable (X) on the dependent variable (Y).
All of the above

5. When the sample size increases,
Power increases
Power decreases
Effect size increases
Effect size decreases

6. When the effect size increases,
Alpha level increases
Sample size decreases
Power increases
Power decreases

7. When the alpha level increases,
Effect size increases
Sample size decreases
Power decreases
Power increases

8. When the test is changed from two-tailed to one-tailed,
Effect size increases
Sample size decreases
Power decreases
Power increases

9. Which of the following is NOT recommended for increasing statistical power (choose the best answer)?
increase sample size
use a directional hypothesis and a one-tailed test
change the alpha level from .05 to .10.

10. It is always a good practice to use a bigger sample size in data analysis.
Yes, when the sample size is bigger, the sample is more representative of the population.
Yes, when the sample size is bigger, statistical power is higher.
No, when the sample size is too big, the test is over-powered.
No, when the sample size is too big, the variance is bigger, too.

11. Although it is desirable to use
Although it is desirable to use .8 as the power level, practically speaking what criteria should be taken into account to determine the sample size?
How much money can I spend?
How much time can the researcher spend?
How soon the deadline is coming?
All of the above

12. The pre-cautionary principle suggests that we should side with ______
the null hypothesis
The alternate hypothesis

13. According to some scientists, extraordinary claims require extraordinary evidence. Therefore, our default position should be ______
the null hypothesis
The alternate hypothesis