Data analysis is important from two points of view: first, it enables a large mass of information to be reduced to a reasonable compass, and second, it assists in the interpretation of experimental results against some framework of theory. The purpose of this text is to provide a practical introduction to numerical methods of data analysis which have applica­ tion in the field of experimental chemical kinetics. Recognizing that kinetic data have many features in common with data derived from other sources, I have considered it appropriate to discuss a selection of general methods of data analysis in the early chapters of the text. It is the author's experience that an outline of these methods is not always easy to locate in summary form, and that their usefulness is often not sufficiently appreciated. Inclusion of these methods in the early chapters has been aimed at simplifying discussion in the later chapters which are more particularly concerned with kinetic systems. By the provision of a number of worked examples and problems, it is hoped that the reader will develop a feeling for the range of methods available and for their relative merits. Throughout the text, the mathematical treatment has been kept relatively simple, lengthy proofs being avoided. I have preferred to indicate the 'sense' and usefulness of the various methods rather than to justify them on strict mathematical grounds.