Some variables, of course, are strings – text information. You might be interested in how many times in your data a certain string turns up. In our case, the ports of embarkation (variable: majbyimp) and disembarkation (variable: mjselimp) are string variables, indicating the places where the majority of people were taken on board and transported to.
We might be interested to see which the main port of embarkation for ships whose home port of Liverpool was. As we have nearly 5000 voyages as cases, it would be laborious to count them all by hand. By performing a Frequencies operation, SPSS will count them for us.
To perform a frequencies analysis, use Analyze | Descriptive Statistics | Frequencies.
This opens the Frequencies dialog box. Move the variable of interest to the right column using the arrow.
In this case the variable is majbyimp. Click on OK and the process will run, and the output will be displayed on the output screen of SPSS.
The output consists of two tables. The first tells you how many valid cases are present in the dataset, and how many invalid (remember we removed the blank entries earlier, using the Missing Values function).
The second table gives you the main results. Here we can see that the bulk of the voyages, 36% of the cases for which we have data, went to the Bight of Biafra and Gulf of Guinea Islands.
Durham SPSS 