Hypothesis Testing

Question 1

observed differences are due to random variation rather than systematic differences

Answer 1

null hypothesis - hypothesis of no difference

Question 2

there are real systematic differences between observed groups

Answer 2

alternative hypothesis - hypothesis of difference

Question 3

null vs alternative hypothesis

Answer 3

hypothesis testing

Question 4

hypothesis test that does not assume direction

Answer 4

two tailed test

Question 5

hypothesis test that does assume direction

Answer 5

one tailed test

Question 6

(sample stat - value of population parameter under Ho) / std. error of sample statistic

Answer 6

test statistic

Question 7

what are the 4 probability distributions

Answer 7

t, z, chi squared, and f test

Question 8

evidence required to reject the null

Answer 8

the level of significance

Question 9

reject the null when the null is false

Answer 9

correct decsion

Question 10

reject the null when the null is true

Answer 10

type 1 error

Question 11

do not reject the null when the null is false

Answer 11

type 2 error

Question 12

do not reject the null when the null is true

Answer 12

correct decision

Question 13

how to define the level of significance

Answer 13

researcher decides

Question 14

probability of correctly rejecting the null hypothesis

Answer 14

power of the test

Question 15

formula for power of a test

Answer 15

1-beta or probability of a type 2 error

Question 16

whats the trade off between significance and power

Answer 16

as the likelihood of a type 1 error increases(decreases) the likelihood of a type 2 error decreases(increases)

Question 17

how to decrease type I and II errors

Answer 17

increase power

Question 18

p-value

Answer 18

value of significance below which we would reject the null hypothesis

Question 19

t test for mean works if: (2)

Answer 19

sample is large or normally distributed

Question 20

z-test distribution mean testing:

Answer 20

know population variance or not

Question 21

test concerning difference of sample means

Answer 21

t test where distribution is normal and population variance is equal

Question 22

test concerning a single variance

Answer 22

chi-squared

Question 23

test concerning equality or inequality of 2 variances

Answer 23

F-test

Question 24

tests of correlation

Answer 24

t test
spearman rank correlation

Question 25

how to calculate spearman rank correlation

Answer 25

calculate the differences in ranks between x and y

Question 26

parametric vs non-parametric test

Answer 26

parametric - concerned with parameters or specific assumptions
non-parametric - use when don’t know about population distribution