Quiz (Chapter 18)
Statistical Tests on Ranks (Nonparametric
Tests)
Introduction
 The simplest kind of quantitative data involve _____.
 Test procedures such as the median test and the MannWhitney U test
are called ______ tests.
Obtaining Ranked Data
 In how many different ways can a researcher "produce" data that take
the form of ranks?
 In Excerpt 18.2, what data were used in computing the Spearman correlation?
 The 1st of the 2 numbers recorded by the 2nd researcher.
 The 2nd of the 2 numbers recorded by the 2nd researcher.
Reason for Converting Scores on a Continuous Variable into Ranks
 Test procedures designed for use with ranks involve ____ (fewer/more)
assumptions than procedures designed for use with interval or ratiolevel
data.
 Unequal or small sample sizes prompt many researchers to ____ (use/not
use) tests based on ranks.
 (T/F) The total scores people earn on a Likerttype attitude inventory
are probably only ordinal in nature.
The Median Test
 The median test is used to compare 2 or more groups that are _____
(independent/correlated).
 In comparing 3 groups with a median test, how many medians would
appear in the test's null hypothesis?
 In comparing 3 groups with a median test, how many medians need to
be computed from the sample data?
 The calculated value in a median test is referred to as ___.
 t
 F
 c2
 (T/F) If, in Excerpt 18.10, group C's median healing time had been
12 weeks (rather than 14 weeks), the null hypothesis might have been rejected.
The MannWhitney U Test
 The MannWhitney U test test is used to compare 2 groups that are
_____ (independent/correlated).
 In the study associated with Excerpt 18.11, the sums of ranks for the 2
institutions were quite _____ (similar/different).
 The task of interpreting a significant result from a MannWhitney
U test is _____ (easy/difficult).
 (T/F) If the U test leads to a rejection of Ho,
the populations might differ in their means, medians, or modes.
 There is a ______ (direct/indirect) relationship between the size of U, the
calculated value, and the size of p.
The KruskalWallis H Test
 The KruskalWallis H test is used to compare 3 or more groups that
are _____ (independent/correlated).
 (T/F) In both the KruskalWallis and MannWhitney tests, a "sum of
ranks" is computed for each sample.
 The information in Excerpt 18.12 shows that there is a(n) _____ (direct/indirect)
relationship between the size of H and the size of p.
 In a KruskalWallis test, Ho is rejected if the calculated
H is ____ (smaller/larger) than the critical value.
 In Excerpt 18.14, how many MannWhitney U tests were conducted in the post hoc
investigation following the significant KruskalWallis result?
The Wilcoxon MatchedPairs SignedRanks Test
 Wilcoxon's test is used to compare __ (how many?) sets of scores
that are _____ (independent/correlated).
 The calculated value in a Wilcoxon matchedpairs signedranks test
is referred to by what capital letter?
 In Excerpt 18.15, what would have happened to T and p
if the two sums of ranks had been more similar?
 Both T and p would have been smaller.
 T would have been larger but p would have been smaller.
 T would have been smaller but p would have been larger.
 Both T and p would have been larger.
 In a Wilcoxon test, Ho is rejected if the calculated value
is ____ (smaller/larger) than the critical value.
 A significant T suggests that the 2 populations differ in what way,
assuming they have the same shape?
Friedman's TwoWay Analysis of Variance of Ranks
 Friedman's test is used to compare __ (how many?) sets of scores
that are _____ (independent/correlated).
 Which parametric ANOVA is analogous to the Friedman twoway analysis
of variance of ranks?
 If each of 3 people tastes 3 soft drinks and then ranks them, what
should you expect the "sum of ranks" to be for any of the beverages
if the null hypothesis (that the 3 beverages are equally good) is true?
 Read Excerpt 18.16 and the paragraph above it. Based on these
descriptions of the study, how many sets of ranks were there?
 3
 25
 49
 It's impossible to tell based on the information provided.
 If the Friedman test yields a significant result, what test is likely
to be used in a post hoc investigation?
LargeSample Versions of the Tests on Ranks; Ties
 (T/F) A test on ranks made via a ztest (due to large samples) can
be thought of as a "normal curve test."
 The _____ test can be thought of as the "smallsample" version of
the median test.
 In Excerpt 18.17, which number(s) allow us to know that data came from more
women that men?
 The 3 means (12, 16, and 5)
 The standard deviation (21)
 The calculated value, z (7.15)
 The probability, p, associated with z (<.001).
 The regular median test is inherently a ______ (smallsample/largesample)
test.
 (T/F) When ties occur in tests on ranks, the only thing a researcher
can do is discard the tied scores.
A Few Final Comments
 Nonparametric tests ___ (are/are not) based on the assumption that
the data come from random samples.
 In Excerpt 18.11, the means and standard deviations for the two samples
____ (do/don't) suggest the presence of "overlapping distributions."
 The last sentence in the 2nd paragraph on p. 454 urges you not to
use _____ as the criterion for judging the worth of empirical studies.
 how large or small the sample size is
 how "impressive" the databased plevel is
 what alpha level was used
 whether H_{o} is or isn't rejected
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