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Meta-Analysis Activity

NAME_____________________________

A researcher wished to complete a meta-analysis reviewing studies that explored the relationship between the amount of self-disclosure and the degree of liking reported between recent acquaintances. In addition to effect sizes, researchers had a group of raters assess study quality on a scale ranging from 0 (lowest possible quality) to 10 (highest possible quality). Other moderator variables include the date of publication of the study, the number of independent variables in the study, whether the relational partners were same-sex or opposite-sex partners, and whether the samples were college students or adult populations. The researcher has decided to use r as the measure of effect size.

Study and Date

Sample size (n)

Direction of Relationship

R

Number of Variables in Studies

Quality Ratings

Sex composition of the relationship pairs

1 = same sex

2=opposite sex

Type of Sample:

1 = college

2 = adult

Fisher’s Zr

1975

100

+

.33

3

8

1

2

 

1980

120

-

-.15

2

6

2

1

 

1990

290

+

.28

5

8

2

1

 

1990

80

+

.40

3

9

2

2

 

1992

150

+

.22

4

4

1

1

 

1997

140

-

-.20

4

5

2

1

 

1999

170

+

.30

5

7

1

2

 

2002

300

+

.33

2

6

1

2

 

2002

175

+

.25

2

8

1

1

 

·  The researcher wanted to identify relationships that are at least a “slight” relationship. State the hypothesis for this type of relationship:

 

·  In the column on the far right of the table, insert the Fisher’s Z transformed correlation for each of the studies.

·  What would be the mean effect size for these data?___________________________

 --what would be the mean effect size if transformed back into raw scores?

HINT: To transform a ZFisher correlation back to an untransformed correlation, the following formula is used: .

·  What is the result of the diffuse comparison test?_____________________________

 

Focused Comparison Tests:

a.       For the number of independent or predictor variables moderator variable:

1.      What is the Z value for the focused comparison test of the “number of variables” moderator variable?_______________________________________________________

HINT: The Linear Contrast coefficients for nine studies are:

-4     -3      -2     -1     0      1      2     3     4

2.      Is this effect statistically significant with an alpha risk of .05?______________

b.   For the sex composition of the relationship pairs moderator variable:

1.      What are the orthogonal polynomials for each of the studies in the following arrangement?____________________________________________________________

Study Date

1975

1980

1990

1990

1992

1997

1999

2002

2002

Sex Composition

1

2

2

2

1

2

1

1

1

Polynomial with Ties

 

 

 

 

 

 

 

 

 

2.   Is this effect statistically significant with an alpha risk of .05?______________

c.   For the type of sample moderator variable:

1.   What are the orthogonal polynomials for each of the studies in the following arrangement?___________________________________________________________

Study Date

1975

1980

1990

1990

1992

1997

1999

2002

2002

Type of Sample

2

1

1

2

1

1

2

2

1

Polynomial with Ties

 

 

 

 

 

 

 

 

 

 2.   Is this effect statistically significant with an alpha risk of .05?_____________

d.   There are three continuous variables in the study: the study date for publication, the number of variables, and experts’ quality ratings.

·        What are the intercorrelations for the continuous moderator variables in the study? ____

_______________________________________________________________________

         _______________________________________________________________________

     ·        What is the correlation between each of these moderator variables and the effect size observed?

_______________________________________________________________________

·        What interpretations must be made about the influences of moderator variables?

            ________________________________________________________________________