7 2 Some Basic Steps in SPSS FILES FOR CHAPTER 2:.SPSS_demo.sav Chapter 2_Basic steps.spv You can find them in the Data files folder of the zipped file you downloaded from http:// oluwadiya.sitesled.com/files/ SPSS%20Stuff.htm WHEN FILES WON T OPEN If you want to open a file by double-clicking on it, the file has to be associated with the program in which it was created. If you double-click on the SPSS_ demo.sav file, and instead of SPSS opening it, you see a warning dialog box that says Windows can t open this file, it means that you have not installed SPSS on your computer. The second likely reason may be that you have installed SPSS, but Windows has not associated. sav files with SPSS on your PC. Unlike other computer programs you may have come across, SPSS has many user interfaces. For example, the user interface for entering data is different from the user interface in which the result of your analysis are displayed. These interfaces are called Windows. In this chapter, you will learn how to navigate through the different kinds of windows in SPSS. You will also practice the most commonly used procedures. Opening Data Files As it is common with most windows programs, there are two ways to open a file in SPSS. In both methods, you must know the location of the file in your computer before you can open it. We shall be opening one of the files you downloaded from the internet. Method one: Double-Clicking. This is the easiest way to open a file. In Windows explorer, navigate to the folder where you saved the files you downloaded from the internet. Double-click on SPSS_Demo.sav to open it. Method two: Opening from within SPSS: Open SPSS. In the dialog box that comes up (See Figure 1-1 on page 1), select the Open an existing data source option, and click on the file on the list. If the file is not on the list, click on the More files option to browse for the file on your computer. In the Open Data dialog box that comes up, navigate to the folder where you kept the file. Click on SPSS_Demo.sav to select it, then click the Open button. Data Editor Windows The Title Bar is the horizontal bar at the top of the window. It bears the name of the current FIGURE 2-1: The two images compare the title bar of an unsaved and a saved file. Image 1 Image 2 file you are working on. However, if you have not saved the file, it will be given the name Untitled. In Figure 2-1, the file in Image 1 has not been saved while the one in Image 2 has been saved with the name SPSS_Demo. The Menu Bar (labelled 2 in Figure 2-1) is the horizontal bar just below the Title Bar. Beneath the menu bar is the Tool Bar (labelled 3 in Figure 2-1) which contains the icons of the most commonly used commands. By clicking any of the buttons, you will be able to run the appropriate command. Click any of the Menu Bar items to show its submenus. In Figure 2-2 (A), we have clicked FIGURE 2-2: Submenus come in two ways: (A) Followed by ellipsis and (B) Followed by arrowheads. Motivation is what gets you started. Habit is what keeps you going...anonymous.
8 Chapter 2 DIALOG BOXES THAT WILL NOT DIALOG! Some dialog boxes will not allow you to manipulate them. They are message boxes for display error messages and information indicating why a requested task cannot be effected. on TRANSFORM to show its submenus. There are two types of submenu items; some, like Compute Variable..., have an ellipsis after them; clicking these submenus will bring up a dialog box through which you can immediately execute the command. Certain other submenus, such as the one shown in Figure 2-2 (B), Descriptive Statistics, have black arrowheads to their extreme right, which causes yet another sets of submenus to unfold. These offshoots e.g. Frequency in Figure 2-2 (B) are secondary submenus. Clicking on a secondary submenu brings up a dialog box that will execute the submenu command. When a menu item is dim or not visible, the command is not suitable for the type of data being analyzed. What are Dialog Boxes? FIGURE 2-3: Components of a typical dialog box exemplified by the Frequencies dialog box. WAYS TO SELECT SEVERAL VARIABLES AT THE SAME TIME If you want to select more than one variable at a time. This can be done in two ways: a) Select adjacent variables by holding down the shift key on the keyboard as you click each variable. b) Select non-contiguous variables by holding down the control key on the keyboard as you simultaneously click each variable. Dialog boxes are used to instruct SPSS to complete a task or procedure. Understanding how to use Dialog Boxes is central to data manipulation and analysis in SPSS. Dialog boxes appear when you click a menu or submenu item with an ellipsis trailing after them. They contain options you can select. After you specify the options, you then choose a command button to execute the procedure. Open the file SPSS_Demo.sav in the Data Files folder of the items you downloaded from the Internet. Go to the menu bar and click ANALYZE. Click again on DESCRIPTIVE STATISTICS and then on FREQUENCIES Dialog boxes also have Title Bars which bear the name of the selected menu or submenu function. In Figure 2-3, the title bar shows Frequencies, which is the submenu item that we selected. Most Dialog boxes are constructed along similar lines. We will use Figure 2-3 to illustrate a typical Dialog box. SECTION 1 is a box which we will refer to as the variable list box. It contains the variables from which you can make your selections. If there are more variables than can fit in the box, scroll bars are provided so you can scroll through the list. Sometimes, some variables may be absent from a dialog box because such variables are not appropriate for procedures that are carried out with the particular dialog box. For example, categorical variables will not be listed in Dialog boxes for procedures, such as Means or Correlations which require continuous data. When you click a variable in the box, it will be highlighted in blue, indicating that it is selected. The arrow (A in Figure 2-3) immediately to the right of the variable list box will become bold. You have to click this arrow to move the selected variable(s) in section 1 to the box in section 2. Life in abundance comes only through great love...elbert Hubbard.
Some Basic Steps in SPSS 9 SECTION 2 is the box into which you move the selected variable(s) in the variable list. You do this by clicking the arrow button. Observe that the box is labelled Variable(s). Sometimes this label is different, but the functions remain the same. SPSS will use only the variables in this box for its analysis. SECTION 3 contains small white boxes called Check boxes. Each check box has a label detailing its function. When check boxes are selected, SPSS will carry out the assigned action. In Figure 2-3, the label is Display frequency tables. Click in the check box with the left mouse button and a tick mark will appear in the box to show that it has been selected. To deselect it, click again in the check box. Check boxes are not mutually exclusive, you can therefore select as many of them as you need. SECTION 4 contains the following command buttons: OK executes the procedure and bring up an output viewer window. Click this button only when you are satisfied with your choices. Paste saves all your selections into a syntax window. Reset returns everything in the dialog box to its default state. All the selected variables will be returned to the variable list box and all selections in the main and supplementary dialog boxes will become deselected. Cancel removes the dialog box without carrying out the procedure. This can also be done by clicking the X button on the upper right hand corner. Help brings up a window with instructions and explanations relating to the procedures in the dialog box. Be warned though, these helps are cryptic and may be difficult to understand. In other words, you need helps to understand the help! You can also access the help window by clicking on the? button in the upper right hand corner. SECTION 5 contains a set of buttons that when clicked will bring up other dialog boxes for CONTINUE VERSUS OK Supplementary dialog boxes use the button Continue to execute their actions while main dialog boxes utilize the button OK. WHAT S IN A NAME? Prior to SPSS 16, output files were saved as files with the.spo extensions; but from version 16 and above, extension of output files had been changed to.spv. SPSS 16 and above can no longer open output files generated by earlier versions and vice-versa. Data files, on the other hand, still have the same extension and can be opened by all versions of SPSS. supplementary analysis under the main procedure. For example, click the Statistics button. This will bring up the Frequencies: Statistics dialog box shown in Figure 2-4. As Figure 2-4 shows, the various options in the dialog box allow us to generate other statistics like percentiles, measures of central tendency and dispersion along with frequency. Click Continue to confirm the options and return to the main dialog box. The SPSS Statistics Viewer Window FIGURE 2-4: Secondary dialog box. Note that it has a Continue button instead of the OK buttons in main dialog boxes. Secondly, the title is always compound, with a full colon between the names. Compare this title to the title in Figure 2-3. No love, no friendship, can cross the path of our destiny without leaving some mark on it forever...francois Mocuriac.
10 Chapter 2 HELPFUL TIPS In an outline view pane, a - sign indicates that the folder is open and clicking it hides its subfolders. A + indicates that the subfolders are hidden and you can reveal them by clicking the + sign. FIGURE 2-5: The outline pane of the SPSS Statistic Viewer window. Note the tree-like structure which is similar to the arrangement in Windows Explorer. Clicking OK in any dialog box or running a syntax command will generate the result of your analysis in a separate window called the SPSS Statistics Viewer window. We will be using the file Chapter2.spv for illustration. Go to the Output Files folder of the items you downloaded from the Internet, and double-click on the file. The SPSS Statistics Viewer window comes up. The bars on top of the window are arranged in a fashion similar to the Data Editor window. When you have not saved the work, it is automatically named Output X, where X is an integer. For example it will be Output 1, if it is the first unnamed viewer window you have opened, and Output 2, if it is the second, and so on. You should click on FILE on the menu bar and choose Save. In the Save As dialog box, enter the name with which you want to save the output in the File Name box. In this instance, type SPSS demo 2. Then click the Save button. The Viewer window has two columns; the smaller one on the left is the Outline Pane, which displays the output in an hierarchical list, while the larger one, the Output Display Pane is on the right, and it displays the results in full. Using the Outline Pane Click on + output to display them again. In a similar manner to the arrangement of files and folders in Windows Explorer, the items in the outline pane are arranged in hierarchies (see Figure 2-5). Some of the items in the outline pane are preceded by little boxes with either a + (Arrow 1) or a - (Arrow 2) sign. Items with preceding little boxes are folders. Folders can contain other folders (called sub-folders) and files. A - box preceding a folder means that the folder is open, and everything it contains is on display. On the other hand, a + box preceding a folder means that the folder is closed, and everything it contains is hidden. The folders that become hidden when you click on the negative sign are called sub-folders. In our example, all the folders in the output pain are sub-folders of the Output folder and Title Notes and Statistics are fields in the Frequency sub-folder. Click on - output to hide everything, then Click the little red box immediately to the left of Output. As Figure 2-6 shows, everything in the Outline Pane becomes highlighted in blue. Observe how all the structures in the Output Display Pane become surrounded by selection boxes. FIGURE 2-6: How to select a folder and all its contents. You should click that little box. Courage is not the lack of fear, it is acting in spite of it...mark Twain.
Some Basic Steps in SPSS 11 PRACTICE MAKES PERFECT Click on other items in the root menu for further practice. FIGURE 2-7: How to select a single file in the outline pane FIGURE 2-8: Repositioning items in the outline pane of the Statistic Viewer window Next, click on the file Gender and observe how this item alone was outlined (see Figure 2-7). In the Output Display Pane, a selection box is now placed around the gender bar chart. By dragging an item within the outline pane, you can move it from one position to the other within the Output Display Pane. Click on the item State of origin within the outline view with the left mouse button and while holding the button down, drag it up below the folder, Output and then release the button. Figure 2.8 shows that the table, State of origin has been moved up above everything else in the output display view. The small red arrow to the left of the item you click moves as you drag the mouse button. It indicates the current position to which the item will be moved if you release the mouse button that moment. To rename an item in the Outline Pane, double-click the item, and enter the new name. Using the Output Display pane To select an item in the Output Display Pane, click on it once. A selection box will be formed around the item to show that it is selected. In addition, a little red arrow will be placed next to FIGURE 2-9: Table in editing mode: The header row is highlighted in black, the table is surrounded by dash lines and the menu bar is altered by the addition of Insert, Pivot and Format. Three menus that are useful for editing tables. Love cures people; both the ones who give it and the ones who receive it...karl Menninger.
12 Chapter 2 FIGURE 2-10: The table context menu. (Generated when you right-click a table). PRACTICE MAKES PERFECT Right-click on different items in the Statistics Viewer and observe how the context menu keeps changing as you click different items. the item. Click anywhere outside the selection box to deselect the item. Once an object is selected in the output display pane, the object can be cut, copied or deleted using the appropriate submenu in the EDIT menu. The last item on the EDIT menu is for editing the selected item either in the current window or in a separate window. If you have deselected Statistics, select it once again, and in the EDIT menu, scroll down to the EDIT CONTENT and click the In Viewer submenu. Figure 2.9 shows the table becomes surrounded by dash-line box. Now take a closer look at the menu bar and observe that three new menu items have been added; PIVOT, INSERT and FORMAT. These menus are used to adjust the properties of the table and its cells. Furthermore, the tool bars have disappeared. The other option on the EDIT CONTENT submenu is In Separate Window. As the name suggests, choosing this option opens the selected table in a separate window - the SPSS Pivot Table Editor. What you can do in this window is similar to what you can do using the EDIT submenu. Finally, in the output display panel, right click on a table; the table context menu springs up. As shown in Figure 2-10, the menu contains most of the options in the EDIT menu. The context menu offers an immediately available list of command that can be applied. The content of the list will depend on the object you right click. In SPSS 15 and below, the statistics coach command is available in the context menu when you right-clicked a table. Sadly, this very convenient command has been removed in later versions. However, the same function can still be (albeit, less conveniently) accessed using the HELP menu. Never discourage anyone who continually makes progress, no matter how slow...plato.