5.5 Try It! Exercises

1. Creating New Variables, Transforming Variables & Adding Verbal Labels

For these exercises, you will need to open the example1.sav file that you created in Chapter 2. You will be asked to type in scores on two new variables in this data file:

• student attitudes towards computer-computation of statistics (attitude1)
• student attitudes towards hand-computation of statistics (attitude2)

1. Enter the scores on the two new variables we have added to this file (Figure 5.21).

Assume that these scores represent favorableness of the attitude for computer/hand computation:

• attitude1: Attitude towards computer computation (1 = Unfavorable; 5 = Favorable)
• attitude2: Attitudes towards hand computation (1 = Unfavorable; 5 = Favorable).

Note that before you enter the scores, you should first click the Variable View tab and type in the two variable names (Figure 5.22).

Then click the Data View tab and enter the scores for these two new variables shown in Figure 5.21.

2. Use the Compute Procedure explained in Section 5.2a to compute a new variable (attitudetot) which is the sum of the two new attitude scores:

• Select Transform, Compute from the Data Editor menu
• Type attitudetot in the Target Variable: box of the Compute dialog window
• Type attitude1+attitude2 in the Numeric Expression: box
• Click the OK button

When you are finished, the Data Editor should display the new attitudetot variable (Figure 5.23).

3. Use the Recode Procedure explained in Section 5.2b to transform the continuous variable, courses, into a new dichotomous variable, experience, with two categories. Use these recoding rules:

• If the courses score is 2 or lower, then experience = 1 (Low Experience)
• If the courses score is 3 or higher, then experience = 2 (High Experience)

To perform this transformation, select Transform, Recode, Into Different Variables from the Data Editor menu. A Recode into Different Variables dialog window will appear. Do the following:

• Move the courses variable into the Input Variable - > Output Variable pane
• Type experience in the Name: box for the Output Variable
• Click the Change button, then click the Old and New Values button.

The Old and New Values dialog window will appear. Do the following:

• In the Old Value panel, select the Range lowest thru__ button, then type 2 in the box
• In the New Value panel, type 1 in the box, then click the Add button
• Return to the Old Value panel, select the Range __ thru highest button, then type 3 in the box
• In the New Value panel, type 2 in the box, then click the Add button, then click the Continue button.

Last, click the OK button in the Recode into Different Variables dialog window. When you are done the Data Editor window should show the new categorical experience variable with scores of either 1 or 2 (Figure 5.24).

4. Add a descriptive Variable Label and Value Labels for the new experience variable using the procedures explained in Section 5.3b. First click the Variable View tab in the Data Editor.

• Click on the cell in the Label column for the experience variable
• Type Psychology Experience in this cell.
• Click the cell for this variable in the Values column; then click the 3 grey dots (...)

A Value Labels dialog window will appear. To add the labels:

• Type 1 in the Value: box; type Low Experience in the Value Label: box; click the Add button
• Type 2 in the Value: box; type High Experience in the Value Label: box; click the Add button
• Click the OK button of the Value Labels dialog box

When you are finished, the Data Editor window should look like the one in Figure 5.25

5. Click the Data View tab, then save and print this file to submit to your instructor.