Good news! You don't have to know diddly-squat about statistics to be able to come up with well-calculated conclusions and display them in fancy graphs. All you need is the IBM SPSS Statistics software and a bunch of numbers. This book shows you how to type the numbers, click options in the menus, and produce brilliant statistics. It really is as simple as that.
This is fundamentally a reference book. Parts of the book are written as standalone tutorials to make it easy for you to get into whatever you're after. Once you're up and running with SPSS, you can skip around and read just the sections you need. You really don't want to read straight through the entire book. That way leads to boredom. I know — I went straight through everything to write the book, and believe me, you don't want to do that.
The book was designed to be used as follows:
Read the opening chapter so you'll understand what SPSS is. I tried to leave out the boring parts.
If SPSS is not already installed, you may need to read about installing it. That's Chapter 2.
Read the stuff in Chapter 4 about defining variables and entering data. It all makes sense once you get the hang of it, but the process seems kind of screwy until you see how it works.
Skip around to find the things you want to do.
I would mention that you could skip the introduction, but it's too late for that. Besides, you may find some information here that could be useful.
One thing that needs to be clear from the beginning: This book is not about statistics. You will not find one explanation of statistical theory or how calculations are performed. This book is about the things you can do to command SPSS software to calculate statistics for you. The inside truth is that you can be as dumb as a post about statistical calculation techniques and still use SPSS to produce some nifty stats. You have my permission to stop thinking right now.
However, if you decide to study the techniques of statistical calculation, you'll be able to understand what SPSS does to produce numbers. Your main advantage in understanding the process to that degree of detail is that you'll be able to choose a calculation method that more closely models the reality you are trying to analyze — if you're interested in reality, of course.
Shortly before this book went to press, SPSS Inc. was acquired by IBM Corporation. The name of the product referred to throughout this book was changed from PASW Statistics to IBM SPSS Statistics.
Throughout the book you will find examples that use data stored in files. These files are freely available to you. Most of the files are installed with IBM SPSS Statistics in the SPSS installation directory which, by default, is Program FilesPASW (unless you chose another location during installation). A few files were designed for this book and are available on the book's companion Web site:
In every case, the files were especially designed to demonstrate some specific capability of IBM SPSS Statistics.
If you have a question about the data, or if you wish to contact me about some other question you may have, you can reach me at the following e-mail address:
[email protected]
In general terms, this book is for anyone new to SPSS. No prior knowledge of statistics or mathematics is needed, or even expected. In specific terms, this book was written with two groups in mind: students who are not majoring in mathematics but are instructed to use SPSS, and office workers who are instructed to use SPSS to analyze some data.
For most people who generate statistics, the complexity of using the software becomes an obstacle. My purpose in writing this book is to show you how to move that obstacle out of the way with minimum effort.
This book was written so you could read the first part, to get yourself started with SPSS, and then jump around to the other parts as needed. SPSS is a huge piece of software, and you certainly don't want to try to use everything.
The book is filled with step-by-step procedures that you can follow to see how SPSS operates. After you use the provided sample data and step through an example, you'll have a handle on how to apply those steps to your data.
The parts of the book divide the information about SPSS into its major categories. The chapters in each part further divide the information into smaller categories.
Part I: The Fundamental Mechanics of SPSS
The first part is the only one intended to be read straight through. You can gloss over the installation if you already have SPSS installed, but it's still worth familiarizing yourself with the configuration options. You'll come across these configurations later and will need to know what can be changed. This is the only place in the book where you find an obsessively complete example of using SPSS — starting with the entering of gathered data and ending with the generation of rudimentary analyses.
Part II: Getting Data In and Out of SPSS
Input can be tricky. Variables are defined by type and size and a few other things. Part II shows you how to enter data through the main SPSS window or load it from a file. In fact, you can read data from several kinds of files. You can also write data to several kinds of files.
Part III: Graphing Data
In Part III you see how to produce graphs. A large part of the job performed by SPSS is displaying data in graphic formats. SPSS can produce lots of different kinds of graphs. Fortunately, it's easy to do — you simply select variable names and specify how you want them displayed.
Part IV: Analysis
Hidden down inside SPSS are lots of statistical methods. I tell ya, this program manufactures numbers like McDonald's manufactures hamburgers. Part IV explains how to manufacture the numbers you want.
Part V: Programming SPSS with Command Syntax
Part V shows you how to use the SPSS internal command language. You can record procedures in Command Syntax and execute them at will. You can do anything with a Command Syntax program that you can do with the mouse and keyboard. And then some.
Part VI: Programming SPSS with Python and Scripts
Part VI is BASIC talk about programming and scripting SPSS. Anything you can do with Command Syntax or with the mouse and keyboard, you can also do in the Python programming language, and you can schedule the scripts to execute automatically under various circumstances. The scripting languages of SPSS are Sax BASIC and Python 2.6.
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Read the first chapter. Then, if necessary, install SPSS, referring to Chapter 2. Work through the example in Chapter 3.
Now you're up and running. Figure out what you want to do with SPSS — and then refer to the sections of the book that are necessary for doing it. For some tasks (such as programming in Python), you need to read an entire chapter. For other jobs, you need to read only a single section. This book's Cheat Sheet can be found at www.dummies.com/cheatsheet/spss.
Its companion Web site can be found at www.dummies.com/go/pasw.