Backwash is the effect that tests have on learning and teaching. Since the first edition of this book, there has been evidence of a much greater interest in backwash than was previously the case, and its importance in language testing is generally accepted. There has been research, there have been calls for an explicit model of backwash which can be tested empirically, and an entire issue of Language Testing has been devoted to the topic. Backwash is now seen as a part of the impact a test may have on learners and teachers, on educational systems in general, and on society at large.

I have no doubt that over the next few years further research into backwash will result in a better understanding of the processes involved and how different variables contribute to its effect in different situations. Nevertheless, I believe that the basic practical advice which I gave in the first edition of this book for promoting beneficial backwash continues to be appropriate and, for that reason, I repeat it below. It is for readers to decide how the suggestions I make can be implemented in their own situation.

Test the abilities whose development you want to encourage

For example, if you want to encourage oral ability, then test oral ability. This is very obvious, yet it is surprising how often it is not done. There is a tendency to test what is easiest to test rather than what is most important to test.