d. When sample sizes are very small, collapsing will increase the size of the scale
category subsample. For instance, if there are 30 respondents and 25 metric scale
categories (such as age in years), collapsing to a high-low designation using the
median will result in 15 high- and 15 low-age respondents.
3. SPSS cross-tabulations includes several nominal-to-nominal variable nonparametric
statistics options such as contingency coefficient, Phi, Lambda, and others. It also
4. The null hypothesis is omnipresent in associative analysis tests, and it is the
foundation for practically all statistical tests. Instructors are recommended to
continually remind students of the null hypothesis of no association as they review
the various associative analysis tests. It may be worthwhile to recall for students that
the null hypothesis is present in statistical inference tests such as t tests (no difference
between the means of the two groups) or analysis of variance (no difference between
any two group means). For instructors’ information, the null hypothesis concept is
emphasized in the next chapter, particularly with descriptions of bivariate and
multiple regression analyses.
5. Experience has taught that students will become confused with initial encounters with
the various types of frequencies and percentages possible in cross-tabulation tables.
The chapter takes students step-by-step through these slowly; however, Instructors
should consider using class time to review the various steps so students will gain a
conceptual understanding of what each type is and how it is used. At the very least,
students should understand how row and column percentages are useful in identifying
the underlying association if statistical significance is found.
For instructors who want their students to actually compute correlation statistics,
consider end-of-chapter question number 14. It has only 10 cases. The answer to
6. Instructors who desire to emphasize the scatter diagram interpretation of a correlation
should also consider using end-of-chapter question 14. The correlation matrix for all
five variables is provided following as are two scatter diagrams for extreme
correlations (high positive and essentially zero). Students should be able to build the
dataset in SPSS quickly, and they can have SPSS create all possible scatter diagrams.
7. Question 14 is also a useful in-class example. If one has SPSS capabilities in the
classroom, the scatter diagram interpretation of correlation can be illustrated quickly
and effectively using the small dataset provided in question 14.