Using SPSS and PASW/Data Editing
Data organisation and the Data Editor
Opening a data file
The first task will be to retrieve a simple data file to see how data is organised within SPSS. To do this using the menu:
From the File menu, select Open, then select the Data from the resulting sub-menu.
The following dialog box will appear:
In the dialog box pictured opposite, you select the file from the list of files. You can select different drives and directories by clicking the drop-down arrow next to the Look in box. You can retrieve files created by software packages such as Excel by selecting one of the file types from the pull down list in the Files of Type box. This will be covered later in the course. The first file we are going to use is called beer.sav. ? Select this file and click the Open button. The Data View window will contain the following data:
Terminology The data used for this example is based on a survey on various types of beer. The survey obtained the following information about each of the beers: ? the name of the beer ? the alcoholic content (in percent) ? if the beer can be classified as ‘light’ Each of these different types of information is known as a Variable in SPSS and has been given the name beer, alcohol and light respectively. Each variable can be seen running down a column. The rows contain the information for each individual beer tested. The information for each row is known as a case. Each point of data within a cell is a value. To summarise: A case: is a single set of data, in this example the details of one particular beer from the beer survey. Other examples of a case are: one reading from an experiment, the response from one person in a questionnaire, or a set of exam results for one pupil at school. A variable: is a collection of data of the same type. For instance, in our example there are three variables which are the beer name, alcohol content, and whether the beer is light or regular. Other examples of variables are: the amount of drug administered or the temperature in an experiment, the answer to a question in a questionnaire, or the marks for maths and the names of pupils in school exams. A value: is a single item of data which is the intersection between a case and a variable. In our example a value would be, say, the alcoholic content for the third beer surveyed (e.g. 4.9), whether the fifth beer was light or regular, or the name of the 20th beer surveyed. Moving inside the Data Editor Now that some data have been retrieved, you can experiment moving around inside the Data Editor. First there are some points to note: ? The currently selected cell has a thicker border; ? the cell value and co-ordinates appear in the top left-hand corner of the Data Editor; ? the area which shows the current cell value is also the area where new cell values are written or edited by typing in the new value. For straightforward data-entry: ? Use the arrow key ? to move across variables for the first line of data; ? use the Tab key at the end of the first line to go to the second line; ? then use the Tab key to continue with the rest of the data-entry.