During recent years the importance of the subject of statistics has become increasingly recognised and it is now studied not only by statistical specialists but by students from many different disciplines. It has also been recognised that the subject is a suitable one for all levels of educational activity in that it can provide, at quite an early stage, a unifying link between the theoretical and practical sides of many forms of scientific training. This book is an attempt to put across the main principles of statistical methods to those students who are fundamentally interested in the practical applications of the subject, but are not so much concerned with the philosophical bases of the concepts used.

The choice of what to include and what to omit has been difficult, and this second edition of the book includes some new material whilst omitting some of the earlier material. Primarily the aim has been to give a selection of the more commonly used tools and not to provide a complete set of statistical tools for use in each and every situation. The student is then left in the position where he should be able to appreciate what further tools are needed and he can usefully profit from a reading of the more advanced books on the subject that are available. To have included every technique in common use would have lengthened the present book very considerably and destroyed a greater part of its planned utility.