Although Windows 95 makes use of the right-button key on the mouse, we will only be using the left button for now, so when we say to "click" on the mouse button, it will always mean the left one. And unlike Windows 3.x, which usually requires double clicking, a single click will often take you where you want to go. But if one click doesn’t do anything try a double click. (By the way, double clicking means to press the left mouse button twice in rapid succession. If nothing seems to happen, you probably need to double click more rapidly.) Now move your mouse so the pointer touches the "Start" button (don't click anything yet, just let the pointer rest somewhere on the button). Notice that a label appears in a little rectangle, just above the "Start" button, showing "Click here to begin" as shown in Figure 1-2:
These floating labels will usually appear in your active window whenever the mouse cursor moves over a button icon. They will then disappear after a few seconds, so pay attention! You will also see them appear when the mouse rests on one of the graphics in this hypertext book. Each is labelled to correspond to the Figures in the book. Try it out on the one just above. See?
Now that you have found the Start button, click on it once and the Start Menu will appear, and your screen should look something like Figure 1-3.
This is the basic Start Menu, and it too can be customized by adding your most-often used programs to it. Without clicking anything yet, move the mouse pointer up and down the Start Menu. As you encounter each item, it will become highlighted. Nothing other than that will happen with the Help, Run, or Shut Down icons, but letting the pointer hover over Programs, Documents, Settings, or Find will cause other menus to slide out across your screen. The little triangles at the right side of the Start Menu are your clue here. If one is present, that means there are more menus for that item. If this is the first time you are using Windows 95, the Documents menu will say "empty." If you have used programs that saved files, up to 15 of the last ones you saved will show up on this menu. This is a quick way to get back to whatever you were working on recently, since one click will open that file and the applications program it belongs to (such as Word for Windows, SPSS, Excel, etc.).
The important one for us now is the "Programs" icon. Aim the mouse pointer to highlight that icon, and your screen should look somewhat like Figure 1-4,
though with perhaps fewer or different items. Notice the little triangles next to most of the items - you guessed it, more sub-menus. If you are familiar with Windows 3.x or DOS, think of these icons as directories, and their menus as sub-directories or programs.
Move the mouse pointer around on those icons with a little triangle at the right (don't click anything yet) and watch what happens. When the pointer lands on a program icon, it becomes highlighted, and its sub-menu appears. Note that each menu and its sub-menu is in alphabetical order. Whenever you install a new program, it will appear in the Program Menu in its proper order without your needing to tell it anything. Very handy.
On my computer, the SPSS icon is located under Office on the start menu. Point your mouse at "Office" and then look for SPSS 7.5 on the menu to the right. Another menu will open and your screen should look something like Figure 1-5.
One of the choices on this menu will be "SPSS 7.5 for Windows".
Sometimes, getting to a sub-menu can be tricky, especially if you need to move the mouse pointer from one side of the screen to the other, crossing over other programs. If you move quickly, the highlights for those other programs won’t appear and you can safely land on the icon you want. Rather than aiming directly for the icon named "SPSS 7.5 for Windows", just aim anywhere on that sub-menu. Once you are at the sub-menu you want, move the pointer to the exact icon you want and click once. Then wait while SPSS loads. Your screen should now look like Figure 1-6.
Notice a couple of things look different from Windows 3.x. First, the Taskbar is still visible at the bottom of the screen, but now it has an "SPSS" button. Whatever programs you have open will show on the Taskbar, and the one you are currently using will be highlighted.
Next, observe the three small squares in the uppermost right-hand corner of the main SPSS window. The one furthest to the right, with an X in it, is used when you want to close any program you are using. Don’t worry if you click on it accidentally, a dialog box will pop up asking if you want to save anything that changed since the last time you saved your work, before it actually lets you exit the program. You can save and quit, quit without saving, or change your mind about quitting by clicking "Cancel".
The middle of the three small squares allows you to have the window you are working in fill up the whole screen, or to shrink it down to a smaller size. If the middle square shows two cascading rectangles in it, the window is already as big as it can get - clicking on this square will reduce the window in size. Try this now. In this shrunken window, the middle button now shows only one rectangle. Click on it to get back to the full screen view.
The last square, to the left of the other two, has what looks like a minus sign on it. Click this and watch what happens. Whoa, where did everything go? Look at your Taskbar. The button for "SPSS" is still there, but it is no longer highlighted. Click on it and see what happens. Aha. You have just learned how to minimize a window.
We’re not ready to actually use SPSS yet, so let’s close it. There are at least four ways to do this. Move your mouse until the arrow is pointing at the word "File" in the upper-left hand corner of the screen and press the left mouse button once. A menu will appear. Move the arrow so it is pointing at the word "Exit" and press the left mouse button. This should close SPSS.
Let’s try a different way to do the same thing. (Computers usually have more than one way to do everything.) Go back into SPSS and move your mouse until the arrow is pointing at the word "File" in the upper-left corner of the screen and press the left mouse button once, but this time, don’t release the mouse button. Hold the mouse button down and move the mouse down until the word "Exit" is highlighted. Now release the mouse button and SPSS should close. This is called "click and drag" and is another way to use your mouse.
Another way to close SPSS is to point your mouse at the SPSS icon in the upper-left corner of the screen. The icon will be just to the left of the words "Untitled: SPSS Data Editor." Move your mouse to the icon and double click on it. This has the same effect as the first two procedures; it closes SPSS.
You already know the last way to close SPSS. Point your mouse at the X in the upper-right corner of the screen and click on it. SPSS will close.
Now you know how to move your mouse around and how to start and close SPSS. We’ll show you more about Windows, but not much more. If you want to learn more about Windows, there are a lot of books available. The nice thing about Windows is that you don’t have to know much to use it.
Let's get back into SPSS. First, put the data disk that came with this book in your A: drive. (If you are using the B: drive, be sure to change all the instructions so they refer to the B: drive.) Now, point your mouse at the "Start" button on the task bar in the lower left-hand corner of the screen and press the left mouse button. Let your mouse rest on "Programs" and another menu should open. Point your mouse at "SPSS" and still another menu opens. Point your mouse at "SPSS", on it, and SPSS should start. Your screen should look like Figure 1-6. At the very top of the screen, you'll see the words SPSS Data Editor. Just below that line will be the menu bar with the following options: File, Edit, View, Data, Transform, Statistics, Graphs, Utilities, Windows, and Help. Point your mouse at "File" and press the left mouse button. A box will open which is the File menu. Point your mouse at "Open" and press the left mouse button. This opens a larger box called the Open File box. (You're beginning to get the idea of how Windows works.) Here we want to tell SPSS where to find the data file we want to open. In the upper part of the box you'll see "Look in:". Click the down arrow on the "Look in" line and then click A:. Click on the file name, GSS96A.SAV, to highlight it and then click on "Open." In a few seconds, your data matrix will appear.
A data matrix is a very important concept. The rows contain the cases and the columns contain the variables. (If you're familiar with spreadsheets, that's what this is.) Row 1 is case 1, row 2 is case 2, and so on. The top of each column contains the variable name. In this data set the variable names are abbreviations like ABANY and ABDEFECT. Unfortunately the abbreviations for the variable names do not tell you very much. We need some way to find out what these variables are. On the menu bar at the top of your screen, you'll see the word "Utilities". Point your mouse at "Utilities" and click the left button. This will open the utilities menu. Point your mouse at "Variables" and click again. Your screen should look like Figure 1-7.
You'll see a list of all the variables in your data in the left side of the little window. Point your mouse at any of these variables and click. To the right of the variable list you'll see a short description of this variable. For example, point your mouse at the variable "ABANY" and press the left mouse button. This question asked if respondents thought that obtaining a legal abortion should be possible for a woman if she wants it for any reason. The possible answers are YES (value 1), NO (value 2), DK or don't know (value 8), NA or no answer (value 9), and NAP or not applicable (value 0). (Not applicable includes people who were not asked the question.)
Now you know how to get a data file in SPSS and how to find out what the variables are in the file. We will tell you more about this later, but here we just want to give you a brief introduction to SPSS for Windows.
Now that you have the file opened, let's look at some things you can do with SPSS. You're already familiar with the variable ABANY. Let's find out what percent of people surveyed thought it ought to be legal for a woman to have an abortion for any reason. (If you have the Variables window open showing the variable labels and values, point your mouse at the close button and click it.) On the menu bar you will see "Statistics". Point your mouse at "Statistics" and click it. A box opens that looks like Figure 1-8.
This lists the statistical procedures in SPSS. We want to use "Summarize" so point your mouse at "Summarize". This opens another box listing the statistical procedures you can use to summarize your data. Point your mouse at "Frequencies" and click it. This opens the Frequencies box. Since ABANY is the first variable in the data, it's already highlighted. Point your mouse at the right arrow next to the list of variables and click it. The label ABANY will move to the box called Variable(s). This is how you select variables. Point your mouse at "OK" and click it. In a few seconds, the Output Navigator will appear and your screen should look like Figure 1-9.
The Output Navigator is divided into two vertical frames or panes. The left-hand pane contains the outline of the output or information that SPSS gives you. This information is in outline form and can be used to select what you want to view. Simply click on the information you want to look at and that information will appear in the right-hand pane. You can also collapse the outline by clicking on the plus and minus signs in the left-hand pane. The plus sign indicates that the information is collapsed (or hidden) and the minus sign indicates that it is expanded (or shown). You can use the scroll bars on each pane to scroll through the Output Navigator.
The frequency distribution for ABANY is divided into four parts: (1) the title of the table, (2) notes on the table (there aren’t any for this table), (3) a summary of the number of missing and valid observations, and (4) the actual frequency distribution. Click on "Statistics" in the left-hand pane and you will see that there were 1821 valid and 1083 missing cases. Click on "abortion wants for any reason" and you will see the frequency distribution. In Figure 1-9, you can see that 819 people said yes, 1002 said no, 94 said they didn't know, 8 didn’t answer the question, and 981 were coded not applicable. (These 981 respondents were not asked this question. In survey research it's very common to ask some, but not all, of the respondents a particular question. In this case, only about 1900 of the 2900 respondents were asked this question.) Of those who had an opinion, we want to know what percent of the respondents said yes or no, so we should look at the Valid Percent numbers in the table. About 45% of the respondents who had an opinion thought it should be legal, while 55% thought it should be not be legal.
It would be interesting to know if men or women were more likely to favor allowing a legal abortion when the woman wants it for any reason. We’re going to use a crosstab to determine this. Point your mouse at "Statistics" and press the left mouse button. Then point your mouse at "Summarize" and finally, point your mouse at "Crosstabs" and press the mouse button. Your screen should look like Figure 1-10.
The list of variables in your data set is on the left of the screen. We want to move the variable ABANY into the Rows box next to the list of variables. Click on the variable "ABANY" which will highlight it.
Now click on the arrow pointing to the right which is next to the Rows box. Notice that this moves ABANY into the Rows box. Now we need to move the variable SEX into the Columns box. You will have to use the scroll bar in the box containing the list of variables to find this variable. (You can also click anywhere in this box and then type the letter "S" to move to the first variable starting with the letter S.) Point your mouse at the down arrow next to the list of variables and click. If you keep pressing the mouse button, the list of variables will move down and eventually you will see the variable SEX. Highlight it and click on the arrow pointing to the right which is next to the Columns box. This moves SEX into the Columns box. Now your screen should look like Figure 1-11.
We also want SPSS to compute percents for us. Point your mouse at the button labeled "Cells" at the bottom of the screen and click on it. This will open the Crosstabs: Cell Display box. Find the box called "Column" percentages and click on this box. This will place an X in this box and your screen should look like Figure 1-12.
Now click on "Continue" and you will be back to the Crosstabs box. We’re ready to tell SPSS to run the crosstab so click on "OK". After a few seconds your screen should look like Figure 1-13.
Use the scroll bar to look at all the information that SPSS gives you in the Output Navigator.
Now we can see that males and females differ very little in their opinions about a woman obtaining a legal abortion for any reason. Figure 1-13 shows that 44.4% of the males and 45.5% of the females approve of a woman obtaining an abortion for any reason. The difference between these two percents is so small that it could easily be a chance or random difference.
Let's look at some different questions comparing men and women. Who has more education? Is the average age at birth of first child younger for women than for men. We can answer these questions by comparing means. Click on statistics, point your mouse to compare means, and then click on means. Your screen should look like Figure 1-14.
Now we want to put age at birth of first child (AGEKDBRN) and years of school completed (EDUC) in the Dependent List box and SEX in the Independent List box. By now you have a good idea how to do this. Highlight "AGEKDBRN" in the list of variables on the left of the screen by pointing your mouse at it and clicking. Then click on the arrow next to the Dependent List box. Do the same for "EDUC". Now highlight "SEX" and click on the arrow next to the Independent List box. This should move AGEKDBRN and EDUC into the Dependent List box and SEX into the Independent List box and your screen should look like Figure 1-15.
Click on "OK" and the output should look like Figure 1-16.
Women had their first child at an average age of 22.50 years, while the average for men is 25.11 years, a difference of more than two years. Now look at the mean years of school completed for men and women. There isn’t much difference (about 0.35 of a year) between men and women.
Let’s do one more thing in our tour through SPSS. We would expect to find a strong relationship between parent’s education and children’s education. The Pearson Correlation Coefficient will tell us the strength of the linear relationship between father’s education, mother’s education, and the respondent’s education. The closer the correlation is to 1, the stronger the relationship, and the closer it is to 0, the weaker the relationship. Point your mouse at "Statistics" and press the mouse button. Now point your mouse at "Correlate" and then click on "Bivariate". Your screen should look like Figure 1-17.
Now we want to move three variables into the Variables box: EDUC, MAEDUC, and PAEDUC where these variables refer to the number of years of school completed by the respondent and the respondent’s parents. Highlight each of these variables and press the arrow next to the Variables box. Now your screen should look like Figure 1-18.
Click on "OK" and the correlations will appear in your output box. Your output should look like Figure 1-19.
The strongest correlation is between father’s and mother’s education. As we predicted, there is also a fairly strong correlation between respondent’s education and parent’s education.
We can also look at a scatterplot showing the relationship between father’s education and the respondent’s education. Click on "Graphs" in the menu bar and then click on "Scatter". This will open the Scatterplot box. Click on "Simple" and then on "Define". This will open the Simple Scatterplot box. Scroll down the list of variables on the left until you see "EDUC" and click on it to highlight it. Then click on the arrow to the left of the Y Axis box to move EDUC into this box. Scroll down this same list until you find "PAEDUC" and click on it. Then click on the arrow to the left of the X Axis box to move PAEDUC into it. Your screen should look like Figure 1-20.
Now click on "OK" and an output box should open. Your screen should look like Figure 1-21.
Each dot in the scatterplot represents a case in your data set. In general, the higher the education of the father, the higher the education of the child. However, it is far from a perfect relationship. Many fathers with high education have children with less education and many fathers with low education have children with more education.
Overview of Chapters
The remainder of the manual will acquaint you with how to enter new data into SPSS for Windows using the Data Editor. This is covered in Chapter 2. Chapter 3 explains how to take your data, or that collected by someone else, and modify it in a way that makes it easier to understand. Chapter 4 starts the sections where you really get to see the results of your work. In Chapter 4 you will learn how to look at each variable, one at a time. We call this univariate analysis. Chapters 5 through 7 will teach you how to look at two variables at a time, or what we call bivariate analysis. Chapter 6 shows you alternative ways of comparing more than one variable at a time, and Chapter 7 will teach you how to do this using linear regression procedures. Finally, Chapter 8 shows you how to explore relationships among sets of variables using multivariate cross tabulations and multiple regression.