PSYC*2360 Chapter 9: Multigroup Design

Question 1

What is it called when a participant in a study actively attempts to identify the purpose of the research?

Answer 1

Hypothesis-guessing

Question 2

Which term refers to a study’s ability to find differences between groups when there is a real difference (the probability that a study will yield significant results)?

Answer 2

Power

Question 3

What is an easy way to increase the power of a study?

Answer 3

Increase the strength of the manipulation

Question 4

What is a confound?

Answer 4

A variable that the researcher unintentionally varies along with manipulation

Question 5

What is methodological pluralism?

Answer 5

The use of multiple methods or strategies to answer a research question

Question 6

What is a multigroup design?

Answer 6

An experimental design with three or more groups

Question 7

What are three advantages of multigroup designs?

Answer 7

• More efficient (rather than conducting several separate two-group studies, one multigroup study can be run)
• Can identify nonlinear relationships
• Help address potential alternative explanations

Question 8

T or F: having more than two groups or levels of the IV allows for the identification of potential nonlinear relationships.

Answer 8

True

Question 9

What are nonlinear relationships?

Answer 9

Any association between variables that the use of just two comparison groups cannot uncover

Question 10

How are nonlinear relationships often identified on a graph?

Answer 10

As a curved or curvilinear line

Question 11

What is the difference between an empty control group and a placebo group?

Answer 11

• Empty control: A group that doesn’t receive any form of treatment and just completes the dependent variable
• Placebo: A group where participants falsely believe they are getting treatment

Question 12

Which type of control group shows how participants respond under normal conditions?

Answer 12

An empty control group

Question 13

Which type of control group allows for an evaluation of how much participants’ responses on the DV are due to expectations about the potential effects of the IV?

Answer 13

The placebo group

Question 14

What are placebo groups also known as?

Answer 14

Expectancy groups

Question 15

Under what conditions is a one-way ANOVA the appropriate statistical analysis?

Answer 15

When the IV has three or more levels and the DV is measure on a continuous scale

Question 16

What does a one-way ANOVA determine?

Answer 16

Whether responses from different conditions are essentially the same or if the responses from at least one of the conditions differs from the others

Question 17

When conducting a one-way ANOVA, what are assumed to be the two sources of variance?

Answer 17

• Variance between subjects
• Variance within subjects

Question 18

In a one-way ANOVA, by subtracting the mean of each participant’s group from the grand mean, squaring those differences, then adding up the squared difference, what is being calculated?

Answer 18

The between SS

Question 19

In a one-way ANOVA, by subtracting each participant’s score from the mean of their group, squaring the difference, then adding up the squared differences, what is being calculated?

Answer 19

The within SS

Question 20

How is effect size calculated in a one-way ANOVA?

Answer 20

By dividing the between SS by the total SS

Question 21

In a one-way ANOVA, if the variance between groups is simply due to error, will the within SS and between SS be the same or different values?

Answer 21

The same

Question 22

In a one-way ANOVA, if the variance between groups is due to the treatment, will the within SS and between SS be the same or different values?

Answer 22

Different

Question 23

When stating the results from a one-way ANOVA, which two values go in parentheses after the F before the equal sign (F (X, Y)=)?

Answer 23

X= Between-subjects degrees of freedom
Y= Within-subjects degrees of freedom

Question 24

What is the notation for calculated effect size when reporting a one-way ANOVA?

Answer 24

eta^2

Question 25

T or F: ANOVAs not only indicate whether there is any difference among levels of the IV, but they also locate any differences that are present.

Answer 25

False. Indicate whether there is any difference among levels of the IV, but do NOT locate any differences that are present.

Question 26

To test for specific differences when using ANOVAs, what type of analysis is often used?

Answer 26

Exploratory analyses

Question 27

What are exploratory analyses?

Answer 27

Statistical tests that examine potential differences that were not anticipated or predicted prior to conducting the study

Question 28

In the context of a one-way ANOVA, which type of exploratory analyses can be used?

Answer 28

Post-hoc tests

Question 29

What are post-hoc tests?

Answer 29

Statistical tests that examine all possible combinations of conditions in a way that statistically accounts for the fact that not all of them were predicted ahead of time

Question 30

The Tukey HSD test is an example of which type of statistical analysis?

Answer 30

A post-hoc test

Question 31

What are planned contrasts?

Answer 31

Statistical tests that examine comparisons between groups that were predicted ahead of time

Question 32

Although planned contrasts are similar to t-tests, what do they correct for that t-tests don't?

Answer 32

Correct for the number of comparisons

Question 33

Do planned contrasts control for the probability of type 1 or type 2 errors?

Answer 33

Type 1

Question 34

What is an added benefit of planned contrasts?

Answer 34

They allow for the comparison of combined conditions to other conditions in the study

Question 35

What does a chi-square test of independence examine?

Answer 35

Whether the distribution of participants across categories is different from what would happen if there were no difference between groups

Question 36

In a chi-square test of independence, what would need to happen for there to be a significant difference?

Answer 36

There would need to be more participants than expected in some conditions compared to others

Question 37

In a chi-square test of independence, both variables must be what type?

Answer 37

Categorical

Question 38

T or F: A chi-square test of independence is a frequency measure.

Answer 38

True

Question 39

What is the chi-square symbol?

Answer 39

X^2

Question 40

How are degrees of freedom calculated for a chi-square test?

Answer 40

df= (number of rows-1)(number of columns-1)

Question 41

When reporting the results from a chi-square test, what does Φ represent?

Answer 41

Calculated effect size

Question 42

K. Pearson is often associated with correlation, but he also developed which method of statistical analysis?

Answer 42

The chi-square test

Question 43

W. S. Gosset developed which method of statistical analysis?

Answer 43

The t-test

Question 44

R. A. Fisher developed which method of statistical analysis?

Answer 44

The ANOVA (F-test)