Quiz Over the 2nd Half of
Chapter 13 (pp. 324-345)
Two-Way Analyses of Variance
(NOTE: This quiz covers pages 324-345 of the book.
A different quiz covers pages 306-324.)
- (T/F) If none of the two-way ANOVA's Fs turns out to be significant,
no follow-up tests will be conducted.
- Follow-up tests can be used to "probe" significant main effects ___
(and/but not) significant interactions.
Follow-Up Tests to Probe Significant Main Effects
- (T/F) In Excerpt 13.15, if there had been just 2 conditions, no
follow-up test would have been conducted.
- Consider the second set of post hoc results shown Excerpt 13.15.
If these results had been presented in a table with letters attached
to the means, how many different letters would there have been?
- 1 (an "a")
- 2 (an "a" and a "b")
- 3 (an "a," a "b," and a "c")
- If post hoc tests are used to probe the significant main effects
of a 2x3 ANOVA, how many null hypotheses will be tested?
Follow-Up Tests to Probe a Significant Interaction
- (T/F) Researchers usually refrain from interpreting the main effect
F-ratios if the interaction is significant.
- In the middle portion of Figure 13.1, which Source(s) would be "ns"
if the cell mean of 5 is changed to 35?
- In a graph of a cell means, the ordinate and abscissa are usually
labeled with the names of ______ & ______.
- If statistically significant interaction is graphed, the lines in
the graph ___ (will/won't) be parallel.
- Comparing cell means that lie in individual rows and/or individual
columns is a test of _____ _____ _____.
- In Excerpt 13.16, there would have been absolutely no interaction
if the mean of 5.69 had turned out equal to
- Look at Excerpt 13.17. There would have been ____ (more/less) of
an interaction if the bar for the Low Load, Milkshake Salient group
had been shorter.
- If Excerpt 13.19's interaction is graphed, how many lines would
there be in the graph.
- If the follow-up strategy used Excerpt 13.20 had been used in Excerpt
13.18, a total of __ pairwise comparisons would have been made.
- In two-way ANOVAs, planned comparisons ___ (can/can't) be done if
the interaction is not significant.
- In Excerpt 13.21, how many means were involved in each of the planned
comparisons that were conducted?
- It is impossible to determine
Assumptions Associated With a Two-Way ANOVA
- (T/F) The assumptions of a two-way ANOVA are the same as those associated
with a one-way ANOVA.
- Violations of the equal variance assumptions of a two-way ANOVA are
more disruptive when the __'s differ.
- (T/F) In testing the normality and equal variance assumptions, researchers
hope for nonsignificant results.
- Hartley's F-max test focuses on which assumption, normality or
homogeneity of variance?
- If the normality or equal variance assumption seems untenable, the
researcher can either ____ or ____.
- The term "____" means that a statistical tests functions as it should
even if the assumptions are violated.
- An F-test is considered to be ____ (positively/negatively) biased
if it turns out larger than it should.
Estimating Effect Size and Conducting Power Analyses in Two-Way ANOVAs
- Two-way ANOVAs ___ (can/can't) yield results that have statistical
but no practical significance.
- In Excerpt 13.27, the size of d would have been _____ (larger/smaller)
than 0.44 if the mean rating from elementary teachers had been 8.69 rather than 9.69.
- It's better to do a power analysis ____ (before/after) the data are
collected and analyzed.
- (T/F) A strength-of-effect index can be computed for each main effect
F and for the interaction F.
- The two most commonly used strength-of-effect measures are called
_____ and _____.
- Most researchers ___ (do/don't) distinguish between statistical and
practical significance in 2-way ANOVAs.
The Inflated Type I Error Rate in Factorial ANOVAs
- (T/F) Since a 2-way ANOVA with 1 dependent variable yields 3 F-tests,
most researchers divide a by 3.
- If a researcher sets a equal to .05 when
evaluating each of the 3 F-tests, the "______" error rate is equal to
- (T/F) In Excerpt 13.29, the Bonferroni-adjusted alpha level would
have been equal to 0.01 if there had been 5 school levels
(rather than 3).
A Few Warnings Concerning Two-Way ANOVAs
- (T/F) If the research questions are not worth investigating, there's
a fatal flaw in the study than cannot be salvaged by a two-way
ANOVA . . . even if all assumptions are met and all analyses are properly
- In Excerpt 13.20, the researchers report that "This interaction can be
explained by the post hoc analyses that explained that women in the age
category 50 to 59 years had significantly lower scores than men or women
in all other age and gender categories." What two words should be inserted
after the word "years"?
- on average
- without exception
- (T/F) Because a two-way ANOVA is so powerful, its F-tests never lead
to either Type I or Type II errors.
- (T/F) If the main effect means for one of the factors in a
two-way ANOVA turn out to be identical, the null hypothesis associated
with that particular factor should be considered to be true (i.e., fully
Click here for answers.
NOTE: Questions dealing with
the 1st half of Chapter 13 appear on a separate quiz.