This is the fourth edition of the book “Randomization Tests” containing a large number of innovative applications of randomization tests in experimental design, significance testing, computing facilities and other fields. The book focuses more on design than on test statistics. This volume can serve as a practical source book for researchers but, at the same time, it puts emphasis on randomization tests rationale. In comparing with the third edition, this volume gives a more didactical approach in the exposition and it contains many new examples making the book more accessible as a textbook for students in applied statistics. The book contains 15 chapters on topics including statistical tests that do not require random sampling, randomized experiments, between-subject and factorial designs, repeated-measures and randomized, block design and multivariate design, trend tests, tests of quantitative laws, tests of direction and magnitude of effect.