This chapter provides an example of the use of R and SPSS on the basis of a t-test for paired samples, a well-known and simple statistical test used to compare, for instance, the central tendencies of scores obtained before and after a therapy. There are a number of websites which are specifically developed for medical applications. One of them is the commercial program Medcalc, the structure of which is similar to that of SPSS. Excellent handbooks are available for statistical analysis in both SPSS and R. A good general introduction to R is Black. For specific R programs, one can consult their manuals which are available on the internet, or accompanying documentation files. The chapter summarizes the calls for specific programs of the SPSS package as shown in the following. The ‘general’ program listed in the menu bar is written in bold, and the optional programs which appear in the dialog box are in bold and italics.