Читать книгу Interpreting and Using Statistics in Psychological Research - Andrew N. Christopher - Страница 69

To give you some experience creating an SPSS spreadsheet and entering data into a spreadsheet, we’ll use some new data and create a time plot. Table 3.6 contains the number of motor vehicle thefts per 100,000 people in United States between 1995 and 2012 (Federal Bureau of Investigation, 2015). Let’s enter these data into SPSS and create a time plot.

You will need to start a new SPSS spreadsheet. To enter these data into SPSS, we need to first go into Variable View (in the bottom left corner of the spreadsheet). Here, we create two variables: (1) year and (2) motor vehicle thefts per 100,000 people.

Table 3.6

In the first column, titled Name, you need to give each variable a name. I called the first variable Year and the second variable Motor_vehicle_thefts. Notice the underscores to connect the words in this second variable. SPSS does not allow you to have spaces between words in the Name column.

In the second column, make sure your type is Numeric. Although arbitrary, the Width column can be left at its default for our purposes. For the variable Year, change Decimals to zero (0). It makes no sense to have decimal places in the year. For the variable Motor_vehicle_thefts, Table 3.6 reveals they are reported to one decimal place, so for this variable, change Decimals to one (1).

In the Label column, we are allowed to call our variables anything we want. Given the constraints in the Name column, it is a good idea to provide some sort of label to each variable, as I have done here:

When you have a large dataset with many variables, providing a label for each variable is helpful in staying organized, which is something that will become even more important in later chapters.

Finally, move over to your Measure column. Here is where we tell SPSS how the data were measured. Test yourself here. Is the Year variable nominal, ordinal, or scale? How about the Motor_vehicle_thefts variable? Here’s the screenshot to answer these two questions:

In the lower left corner of the screen, switch to Data View, and here’s what you will see:

Now, enter your data from Table 3.6 into your spreadsheet. When you get done, here’s what you will see:

1 Click on Graphs and then on Chart Builder.

2 Choose Line, and then double-click on Simple Line.

3 Drag the Year variable onto the x-axis and the Motor_vehicle_thefts variable onto the y-axis.

4 Now move over to the Element Properties window. In the Statistic box, click on the dropdown menu, and choose Value. Doing so will allow your y-axis to be labeled correctly.

5 Hit Apply at the bottom of the Element Properties box.

6 Then hit OK in the Chart Builder box, and prepare to be impressed.