Math 104

March 18, 2005

SPSS Assignment 5 (due March 25)

Read Chapter 8 in the SPSS text, about cross-tabulations. (Skip the section on bar charts, stacked or otherwise, at pages 143-145.)

Turn in these problems:

Chapter 8 Concepts (page156): Problems 2, 3

Chapter 8 Data Analysis (pp. 160-164): Problems 4abcde, 7, 8, 20a, 22ab.

HINTS AND SUGGESTIONS

Statistical Concepts:

#2. Think carefully of which variable could possibly influence the other. If the values of one variable could tend to influence the values of the other variable, then the former variable (the “influencing” variable) is called independent and the latter variable is called dependent. If neither variable could have any tendency to influence the value of the other variable, then the terms ”independent” and ”dependent” would not apply to this pair of variables.

#3. When you answer the question for each pair of variables, remember your answers to question #2. If you have decided that the first variable in the pair is independent, then you would want to compute row percentages. If you have decided that the second variable in the pair is independent, then you would want to compute column percentages. If you have decided that neither variable is independent, then neither row nor column percentages would be very useful.

Data Analysis:

In all of the exercises it is useful to compute both row and column percentages at the same time when making the cross-tabulations, even though only one of these two percentages may really be of interest. See p.154 for the directions on how to do this. In order to open the dialogue box with which you get row and column percentages, click on the “Cells” button at the bottom of the “Crosstabs” dialogue box. Remember that if you do compute both row and column percentages, then the first number in each cell of the cross-tabulation is the count, the second number is the row percentage and the third number is the column percentage.

#4. In making the cross-tabulation it will be easiest to print out and read if you make “degree” the row variable and make “life” the column variable. Print out your cross-tabulation.

#4d. In answering this question decide which variable you believe is independent. If the row variable is independent, then you should compute row percentages; if the column variable is independent, then you should compute column percentages.

#7. Make a cross-tabulation in order to answer this question. It will be easiest to print out and read if you make “degree” the row variable and make “happy” the column variable. Print out your cross-tabulation.

#8. IMPORTANT: There is a typographical error in this exercise. Change “question 4” to “question 7”. You are doing another cross-tabulation between the variables “degree” and “happy”.

Use “Sex” as the control variable to obtain separate cross-tabulations for men and women. See p.154 for the directions on how to do this. You will want to select “Sex” for “Layer 1 of 1” in the “Crosstabs” dialogue box to do this. Print out your cross-tabulation.

#20a. Make a cross-tabulation in order to answer this question. It will be easiest to print out and read if you make “jobcat” the row variable and make “sexrace” the column variable. Print out your cross-tabulation.

#22b. In answering these questions decide which variable you believe is independent. If the row variable is independent, then you should compute row percentages; if the column variable is independent, then you should compute column percentages.

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