The objective of this book is to help language teachers write better tests. It takes the view that test construction is essentially a matter of problem solving, with every teaching situation setting a different testing problem. In order to arrive at the best solution for any particular problem – the most appropriate test or testing system – it is not enough to have at one's disposal a collection of test techniques from which to choose. It is also necessary to understand the principles of testing and how they can be applied in practice.

It is relatively straightforward to introduce and explain the desirable qualities of tests: validity, reliability, practicality, and beneficial backwash; this last referring to the favourable effects testing can have on teaching and learning. It is much less easy to give realistic advice on how to achieve them in teacher-made tests. One is tempted either to ignore the issue or to present as a model the not always appropriate methods of large-scale testing organisations. In resisting this temptation, I have made recommendations that I hope teachers will find practical but which I have also tried to justify in terms of language testing theory.

Exemplification throughout the book is from the testing of English as a foreign language. This reflects both my own experience in language testing and the fact that English will be the one language known by all readers. I trust that it will not prove too difficult for teachers of other languages to find or construct parallel examples of their own.