module 7

Question 1

null hypothesis

Answer 1

• skeptical viewpoint of the research question
• devils advocate

Question 2

Null hypothesis is typically written as:

a) Ha: statement
b) Ho: statement
c) Ho: numerical values
d) Ha: categorical values

Answer 2

b)

Question 3

alternative hypothesis

Answer 3

• positive viewpoint of research question
• pattern you want to exist
• contains everything not covered by null hypothesis

Question 4

Alternative hypothesis is typically written as:

a) Ha: statement
b) Ho: statement
c) Ho: numerical values
d) Ha: categorical values

Answer 4

a)

Question 5

How should you write your null and alt hypothesis after you have written it out in words

Answer 5

• convert the hypothesis to symbols for stat clarity
• ex. Ho: X1=X2 and Ha: X1≠X2

Question 6

t or f: the null and alternative are mutually exclusive.

Answer 6

true

Question 7

t or f: the alternative hypothesis describe all possible outcomes alone

Answer 7

false, The null hypothesis and alternative hypothesis describe all possible outcomes

Question 8

The ______ hypothesis always includes the equality statement

Answer 8

null

Question 9

directionality

Answer 9

• if there is direction in the null and alt hypotheses in terms of the measurement variable

Question 10

________ hypotheses just state that there should be a difference in the alternative hypothesis, whereas ________ hypotheses state that the difference should be in a specific direction

Answer 10

nondirectional, directional

Question 11

null distribution

Answer 11

• sampling distribution that you get if you repeatedly sample from fictitious statistical population where null hypothesis is true
• The null distribution is the sampling distribution of an imaginary statistical population where the null hypothesis is true

Question 12

The first step in a hypothesis test is to define the ________, and the second step is to establish the ________.

Answer 12

define the null and alternative hypothesis, establish the null distribution

Question 13

what are the two possible outcomes of a statistical test

Answer 13

• it is likely your data could come from the null distribution, you fail to reject the null hypothesis
• it is unlikely that your data could come from the null distribution, you reject the null hypothesis

Question 14

t or f: you can accept the null hypothesis as long as you have enough data to support it

Answer 14

false, you can only fail to reject it

Question 15

what are the two probabilities used in doing a formal hypothesis test

Answer 15

• Type I error rate aka alpha (⍺): the probability of rejecting the null hypothesis when its true
  -P-value: probability of seeing your data under the null hypothesis, area under the curve from the data to more extreme values

Question 16

what is the common set point for type I error rate/alpha?

Answer 16

0.05/5%

Question 17

who/what is the p value determined by

Answer 17

the data

Question 18

If the p-value is less that the Type I error rate (p<⍺)…

a) you fail to reject the null hypothesis
b) you reject the null hypothesis

Answer 18

b)

Question 19

If the p-value is greater than or equal to the Type I error rate (p≥⍺)….

a) you fail to reject the null hypothesis
b) you reject the null hypothesis

Answer 19

a)

Question 20

wording of scientific statements should reflect what two considerations

Answer 20

• strength of inference
• effect size

Question 21

In stating the strength of inference, essentially, you want to acknowledge that your inference is only as good as _______.

a) your sample
b) your study design
c) the data
d) all of the above

Answer 21

c)

Question 22

t or f: effect sizes should be considered for both rejecting and failing to reject the null hypothesis

Answer 22

false, it is when you reject the null hypothesis

Question 23

what does effect size refer to?

a) if the observed difference is meaningful for the research question
b) if the sample can be increased and have the same result
c) how big your sample was
d) if the theorized difference is meaningful for the research question

Answer 23

a)

Question 24

t or f: Type I error is the probability of rejecting the alternative hypothesis when it is correct

Answer 24

false, the null hypothesis

Question 25

t or f: hypothesis testing is used for the null hypothesis not the alternative hypothesis

Answer 25

true

Question 26

what are the two main types of error rates in statistics?

Answer 26

Type I and Type II

Question 27

Type II error rate

Answer 27

• failing to reject the null hypothesis when it actually is false
• probability under the alt distribution

Question 28

Type I error rate

Answer 28

• rejecting the null hypothesis when its actually true
• • probability under the null distribution

Question 29

t or f: because the alternative distribution is typically unknown, the type II error is also typically unknown

Answer 29

true

Question 30

which of the following best describes the relationship between type I and type II error rates?

a) they are independent of one another
b) as the type I error rate decreases, the type II error rate increases and vice versa
c) as the type I error rate decreases or increases so does the type II error rate

Answer 30

b)