Deck 10: Experimental Design and Analysis II

Question 1

If the null hypothesis is true, then the t test should be close to​

A)0.00.
B)±1.65.
C)±1.96.
D)±3.00.

Answer 1

0.00.

Question 2

t_cv = 3.35 and t_obt = -3.55. Based on these results, we​

A)reject H_o.
B)fail to reject H_o.
C)accept H_o.
D)reject H_a.

Answer 2

reject H_o.

Question 3

Concerns for within-subjects designs frequently include _____ and _____.​

A)order effects; nonequivalent control groups
B)carryover effects; mortality
C)carryover effects; order effects
D)all of the options are correct

Answer 3

carryover effects; order effects

Question 4

If a correlated-groups t test and an independent-groups t test both have df=16, which experiment used more participants?​

A)They both used the same number of participants (n=18).
B)They both used the same number of participants (n=17).
C)The correlated-groups t test used more participants.
D)The independent-groups t test used more participants.

Question 5

If researchers reported that, for a correlated-groups design, t(20) = 3.57, p

A)a total of 21 people participated in the study.
B)a total of 22 people participated in the study.
C)a total of 40 people participated in the study.
D)the number of participants cannot be determined.

Question 6

When we use different subjects in each condition, but they are related on some variable or variables, we are using a _____ design.​

A)matched-subjects​
B)between-subjects
C)within-subjects
D)across-subjects

Question 7

A problem for within-subjects designs in which the order of the conditions has an effect on the dependent variable is

A)counterbalancing.
B)order effects.
C)a Latin square effect.
D)the individual differences effect.

Question 8

For a correlated-groups t test, the alternative hypothesis states that​

A)H₀: m₁-m₂ = 0.
B)H₀: m₁-m₂ > 0.
C)H_a: m₁-m₂ = 0.
D)H_a: m₁-m₂ > 0.

Question 9

A mechanism for controlling order effects either by including all orders or treatment presentations or by randomly determining the order for each participants is

A)ordering.
B)counterbalancing.
C)a Latin square.
D)counterbalancing and a Latin square.

Question 10

A design in which the participants in the experimental and control groups are related in some way is a _____ design.​

A)correlated-groups
B)between-subjects
C)across-subjects
D)none of the options is correct

Question 11

_____ is a strength of matched-subjects designs but a weakness of between-subjects designs. ​

A)Equivalency of groups
B)Minimized testing effects
C)Minimized demand characteristics
D)none of the above

Question 12

For a correlated-groups t test, the null hypothesis states that​

A)H₀: m₁-m₂ = 0.
B)H₀: m₁-m₂ > 0.
C)H_a: m₁-m₂ = 0.
D)H_a: m₁-m₂ > 0.

Question 13

A design in which the same participants are used in each condition is a _____ design.​

A)matched-subjects
B)between-subjects
C)within-subjects
D)across-subjects

Question 14

Using the same subjects in each condition in an experiment is to using different subjects in each condition in an experiment as _____ is to _____.

A)between-subjects design; within-subjects design
B)control group; experimental group
C)within-subjects design; between-subjects design
D)experimental group; control group

Question 15

Which of the following are aspects of a study that can increase power?​

A)greater differences produced by the independent variable
B)smaller variability of raw scores in each condition
C)increased sample size
D)all of the options are correct

Question 16

Which of the following t test results has the greatest chance of statistical significance?​

A)t(28) = 1.70
B)t(14) = 1.70
C)t(18) = 1.70
D)t(10) = 1.70

Question 17

_____ are more of a concern for _____-subject designs, but tend not to be as great a concern for _____-subject designs.​

A)Order effects; within; between
B)Order effects; between; within
C)Demand characteristics; between; within
D)none of the options is correct

Question 18

If researchers reported that, for a correlated-groups design, t(20) = 3.57, p​

A)the null hypothesis should be rejected.
B)that you should fail to reject the null hypothesis.
C)the alternative hypothesis was incorrect.
D)the study needs to be repeated.

Question 19

Which of the following is a type of correlated-groups designs?

A)within-subjects designs
B)matched-subjects designs
C)between-subjects designs
D)both within-subjects designs and matched-subjects designs

Question 20

In a research study comparing two conditions, researchers obtain 24 scores from each condition. If this was a within-subjects design, then there were _____ participants in the study.​

A)24
B)25
C)26
D)48

Question 21

When using a correlated-groups t test, df =​

A)n₁ + n₂ - 2.
B)n - 1.
C)n₁ + n₂ - 1.
D)n - 2.

Question 22

Explain what counterbalancing is, how it is achieved, and which confound it helps to minimize.​

Question 23

A researcher believes exercise reduces anxiety in women. She identifies a group of women who had not exercised before, but are now planning to begin exercising. She gives them a 50-item anxiety inventory before they begin exercising and administers it again after 6 months of exercising. The anxiety inventory is measured on an interval scale and higher numbers indicate higher anxiety. In addition, scores on the inventory are normally distributed. The scores appear below.​

a) What statistical test should be used to analyze these data?
b) Identify H₀ and H_a for this study.
c) Conduct the appropriate analysis.
d) Should H₀ be rejected? What should the researcher conclude?
e)If significant, compute the effect size and interpret this.
f)If significant, draw a graph representing the data.
g)Calculate the 95% CI.

Question 24

Imagine that you conducted a correlated-groups t test with 12 participants. For a two-tailed test, the t_cv at α = .05 would be​

A)±1.796.
B)±2.201.
C)±1.782.
D)±2.179.

Question 25

Explain what a Latin square is and how it helps with counterbalancing.​

Question 26

One advantage of the correlated-groups t test over the independent-groups t test is that it reduces the error variance due to​

A)the degrees of freedom.
B)the independent variable.
C)the dependent variable.
D)individual differences.

Question 27

Identify the two types of correlated-groups designs discussed in the text and explain why each is considered a correlated-groups design.​

Question 28

In a correlated-groups design, if n = 20, then df =​

A)20.
B)19.
C)21.
D)40.