[copy from the book]

Who Is This Book For?

This book is, perhaps obviously, for people who already know a statistics
package. While aimed at SAS and SPSS users, many statistics packages
share their main attributes, especially the use of a rectangular dataset as
their only data structure. I expect users of most other statistics packages
could benefit from this book. An audience I did not expect to serve is R
users wanting to learn SAS or SPSS. I have heard from quite a few of them
who have said that by explaining the differences, it helped them learn in the
reverse order I had anticipated. However, I explain none of the SAS or SPSS
programs, only the R ones, and how the packages differ, so it is not ideal for
that purpose.