(d) The twith pooled variances is equivalent to the F
in (a).11.7
11.9 Eta-squared tells us that ap-
proximately 18% of the variability in the severity of
symptoms can be accounted for by differences in treat-
ment, whereas omega-squared tells us that a less biased
estimate would be 12%. Since the Fwas significant,
both of these estimates are at better than chance levels.
11.11 The results are essentially the same as ours.
11.13 where is the grand mean, is the
effect for the jth treatment, and is the unit of error for
the ith subject in treatment j.
11.15 where is the grand mean, is the
effect for the jth treatment, and is the unit of error for
the ith subject in treatment j.
11.17Source df SS MS F
Group 7 44.557 6.365 7.27*
Error 264 231.282 0.876
Total 271 275.839
*p,.05 [F.05 (7,264) 5 2.06]11.19 There is nothing that I can write out here.
11.21
11.23 Transforming time to speed involves a reciprocal trans-
formation. The effect of the transformation is to decrease
the relative distance between large values.
h^2 =.16; v^2 =.14.eijXij=m1tj 1 eij m tjeijXij=m1tj 1 eij m tjh^2 =.182; v^2 =.120.h^2 =.816; v^2 =.796.11.25 Parts of speech are a fixed variable, because we de-
liberately chose which parts of speech to use. Words
within the noun category are most likely random,
because we would probably choose our nouns at ran-
dom (within certain constraints, such as the number
of letters in the word). We would choose nouns at
random because we care how people respond to
nouns in general, not specifically to “house,” “car,”
“tree,” etc.
11.27The F 5 4.88, and we can reject the null hypothesis.
This question addresses differences among all three
groups, rather than simply pairwise differences.
11.29 Analysis of Epinuneq.dat ignoring Interval (see below).
11.31 The three error terms are 2.40, 1.83, and 2.26, for an
average of 2.162, which is, within rounding error, the
average of the 9 cell variances.
11.33 Gouzoulis-Mayfrank et al. (2000) study
(b) The pairwise differences are 3.678, 3.464, and
0.214, and the square root of MSerroris 4.105. This
gives dvalues of 0.896, 0.844, and 0.05.
(c) It is reasonable to tentatively conclude that Ec-
stasy produces lower scores than either the Con-
trol condition or the Cannibis condition, which
don’t differ.
11.35 There should be no effect on the magnitude of the effect
size measure because h^2 is not dependent on the under-
lying metric of the independent variable.744 Answers
Results for Exercise 11.29
ANOVA
ERRORS
Sum of Squares df Mean Square F Sig.
Between Groups 147.970 2 73.985 36.197 .000
Within Groups 241.187 118 2.044
Total 389.157 120Results for Exercise 11.33
ANOVA
PERFORMANCE
Sum of Squares df Mean Square F Sig.
Between Groups 238.738 2 119.369 7.082 .001
Within Groups 1365.214 81 16.854
Total 1603.952 83