effect size and power

Question 1

what is a type I error?

Answer 1

incorrectly rejecting the null hypothesis: nothing happened but we said it did

Question 2

what is a type II error?

Answer 2

incorrectly retaning the null hypothesis: something happened but we said it didnt

Question 3

what is power:

Answer 3

The probability of correctly rejecting the null hypothesis: say something happens when it happens

Question 4

what affects power?

Answer 4

alpha, sample size, population variance, the alternate hypothesis

Question 5

alpha increases_______and________

Answer 5

power, and probability of a type I error

Question 6

increasing sample size (increases/decreases) power

Answer 6

increases

Question 7

lowering population variance (increases/decreases) power

Answer 7

decreases

Question 8

effect size is a measure of:

Answer 8

the size of of the effect of what is being measured

Question 9

the diffrence between a priori power and a retrospective is:

Answer 9

one measure estimated needed power before the test (priori power) one calculates needed power after the test is completed (retrospective)