RESEARCH METHOD COHEN ok

588 CHOOSING A STATISTICAL TEST
Box 26.3
Types of statistical tests for four scales of data
Nominal Ordinal Interval and ratio
Measures of
association
Tetrachoric
correlation
Point biserial
correlation
Phi coefficient
Cramer’s V
Spearman’s rho
Kendall rank order
correlation
Kendall partial rank
correlation
Pearson product-moment
correlation
Measures of
difference
Chi-square Mann-Whitney U test t-test for two independent
samples
McNemar Kruskal-Wallis t-test for two related
samples
Cochran Q Wilcoxon matched pairs One-way ANOVA
Binomial test
Friedman two-way analysis of Two-way ANOVA for more
variance
Wald-Wolfowitz test Tukey hsd test
Kolmogorov-Smirnov test Scheffé test
Measures of linear
relationship
between
independent and
dependent
variables
Identifying
underlying factors,
data reduction
Ordinal regression analysis
Linear regression
Multiple regression
Factor analysis
Elementary linkage analysis
(e.g. parents, teachers, students and administrative
staff in a school). Tests which can be applied
to a single group include the binomial test, the
chi-square one-sample test, and the Kolmogorov-
Smirnov one-sample test; tests which can be
applied to two groups include the chi-square test,
Mann-Whitney U test, the t-test, the Spearman
and Pearson tests of correlation; tests which can
be applied to three or more samples include the
chi-square test, analysis of variance and the Tukey
test. We set out some of these tests in Box 26.2. It
is essential to use the correct test for the correct
number of groups.
The statistical tests to be used also depend on
the scales of data being treated (nominal – ratio)
and the tasks which the researcher wishes to
perform – the purpose of the analysis (e.g. to
discover differences between groups, to look
for degrees of association, to measure the
effect of one or more independent variables
on a dependent variable etc.). In preceding
chapters we have described the different scales
of data and the kinds of tests available
for different purposes. In respect of these
considerations, Box 26.3 summarizes some of the
main tests here.