Most of the systems nowadays are becoming highly software intensive. Testing such systems requires us to competently decide which testing techniques to use. However, at present, we have very limited practical information of testing techniques. This includes information like what types of defects a particular technique can be expected to find and at what cost; whether technique's performance depends on program to which it is applied, subject who applies it, the number or the type of faults in the program etc. One way to acquire this type of knowledge is via empirical studies. Empirical studies are crucial in order to evaluate software testing techniques. This book addresses the empirical approach to evaluate software testing techniques. The book is written as a result of knowledge gained by conducting many empirical studies to evaluate software testing techniques. It introduces you to the basics of the empirical studies aimed at evaluating software testing techniques focusing on how to carry out such studies systematically besides presenting the actual empirical studies. It is designed for researchers and students interested in the evaluation of software testing techniques.