Copyright 2010, University of Washington stats.pdf
Reporting a significant t-test for independent groups (µ
1
≠ µ
2
):
UW students taking statistics courses in Psychology had higher IQ scores (M = 121, SD = 14.2) than did those
taking statistics courses in Statistics (M = 117, SD = 10.3), t(44) = 1.23, p = .09.
Over a two-day period, participants drank significantly fewer drinks in the experimental group (M= 0.667, SD =
1.15) than did those in the wait-list control group (M= 8.00, SD= 2.00), t(4) = -5.51, p=.005.
Reporting a significant omnibus F test for a one-way ANOVA:
An analysis of variance showed that the effect of noise was significant, F(3,27) = 5.94, p = .007. Post hoc
analyses using the Scheffé post hoc criterion for significance indicated that the average number of errors was
significantly lower in the white noise condition (M = 12.4, SD = 2.26) than in the other two noise conditions
(traffic and industrial) combined (M = 13.62, SD = 5.56), F(3, 27) = 7.77, p = .042.
Reporting tests of a priori hypotheses in a multi-group study:
Tests of the four a priori hypotheses were conducted using Bonferroni adjusted alpha levels of .0125 per test
(.05/4). Results indicated that the average number of errors was significantly lower in the silence condition (M =
8.11, SD = 4.32) than were those in both the white noise condition (M = 12.4, SD = 2.26), F(1, 27) = 8.90, p =
.011 and in the industrial noise condition (M = 15.28, SD = 3.30), F(1, 27) = 10.22, p = .007. The pairwise
comparison of the traffic noise condition with the silence condition was non-significant. The average number of
errors in all noise conditions combined (M = 15.2, SD = 6.32) was significantly higher than those in the silence
condition (M = 8.11, SD = 3.30), F(1, 27) = 8.66, p = .009.
Reporting results of major tests in factorial ANOVA; non-significant interaction:
Attitude change scores were subjected to a two-way analysis of variance having two levels of message
discrepancy (small, large) and two levels of source expertise (high, low). All effects were statistically significant
at the .05 significance level.
The main effect of message discrepancy yielded an F ratio of F(1, 24) = 44.4, p < .001, indicating that the mean
change score was significantly greater for large-discrepancy messages (M = 4.78, SD = 1.99) than for small-
discrepancy messages (M = 2.17, SD = 1.25). The main effect of source expertise yielded an F ratio of F(1, 24)
= 25.4, p < .01, indicating that the mean change score was significantly higher in the high-expertise message
source (M = 5.49, SD = 2.25) than in the low-expertise message source (M = 0.88, SD = 1.21). The interaction
effect was non-significant, F(1, 24) = 1.22, p > .05.
Reporting results of major tests in factorial ANOVA; significant interaction:
A two-way analysis of variance yielded a main effect for the diner’s gender, F(1, 108) = 3.93, p < .05, such that
the average tip was significantly higher for men (M = 15.3%, SD = 4.44) than for women (M = 12.6%, SD =
6.18). The main effect of touch was non-significant, F(1, 108) = 2.24, p > .05. However, the interaction effect
was significant, F(1, 108) = 5.55, p < .05, indicating that the gender effect was greater in the touch condition
than in the non-touch condition.
Reporting the results of a chi-square test of independence:
A chi-square test of independence was performed to examine the relation between religion and college interest.
The relation between these variables was significant, X
2
(2, N = 170) = 14.14, p <.01. Catholic teens were less
likely to show an interest in attending college than were Protestant teens.