Psych 230

Spring 2006

Jury study data

Gender and Ethnicity of the Sample. Highlighted cells are the ones you need to pay attention to.

Frequency Table

GENDER

Frequency Percent Valid Percent Cumulative Percent
Valid Men 133 44.6 44.6 44.6
Women 165 55.4 55.4 100.0
Total 298 100.0 100.0

Ethnicity

Frequency Percent Valid Percent Cumulative Percent
Valid Caucasian 170 57.0 59.4 59.4
Black 21 7.0 7.3 66.8
Hispanic 57 19.1 19.9 86.7
Other 38 12.8 13.3 100.0
Total 286 96.0 100.0
Missing System 12 4.0

Total 298 100.0


Age range and mean

Descriptive Statistics

N Minimum Maximum Mean Std. Deviation
AGE 298 18 73 26.23 9.579
Valid N (listwise) 298




Oneway analysis of variance (ANOVA) testing the differences among the mean guilt ratings of our eyewitness conditions. Note that the differences between groups are stastically significant, F(2, 295) = 9.36, p < .001.



Descriptives: These are the means and standard deviations that were compared. The highlighted fields are to go in your table and figure
VERDICT

N Mean Std. Deviation Std. Error 95% Confidence Interval for Mean Minimum Maximum
Lower Bound Upper Bound
No Witness 107 4.07 1.824 .176 3.72 4.41 1 7
Eyewitness 97 4.80 1.772 .180 4.45 5.16 1 7
Discredited witness 94 3.73 1.660 .171 3.39 4.07 1 7
Total 298 4.20 1.805 .105 4.00 4.41 1 7

Test of Homogeneity of Variances: Since the result is nonsignificant, ignore this table
VERDICT
Levene Statistic df1 df2 Sig.
.420 2 295 .658

ANOVA: This is the actual test with all the info you need to report the significance of the result.
VERDICT

Sum of Squares df Mean Square F Sig.
Between Groups 57.748 2 28.874 9.358 .000
Within Groups 910.171 295 3.085

Total 967.919 297



Post hoc Tukey tests; The ANOVA told us that overall the differences among group means were real, and not due to chance. The post hoc tests tell us HOW they differed. There are 3 comparisons: NW to EW, NW to DW, and NW to DW. The highlighted Sig column tells you if the means are significantly different or not.




Multiple Comparisons
Dependent Variable: VERDICT
Tukey HSD

Mean Difference (I-J) Std. Error Sig. 95% Confidence Interval
(I) GROUP (J) GROUP Lower Bound Upper Bound
No Witness Eyewitness -.74(*) .246 .008 -1.32 -.16
Discredited witness .33 .248 .377 -.25 .92
Eyewitness No Witness .74(*) .246 .008 .16 1.32
Discredited witness 1.07(*) .254 .000 .47 1.67
Discredited witness No Witness -.33 .248 .377 -.92 .25
Eyewitness -1.07(*) .254 .000 -1.67 -.47
* The mean difference is significant at the .05 level.

Graph

Bar of mean guilt ratings by eyewitness condition