Unit 9 Quiz: Review questions

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.

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

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

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

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

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

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

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.

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.

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

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

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