Factor analysis is an increasingly important tool for understanding and working with quantitative data. It is used in psychology, education (for analysing exam results), medical science, economics and other scientific fields, and allows one to work with statistics from an area where many variables are involved. Even those who are not called on to make use of the method themselves will require some knowledge of it in order to understand books and papers in which it appears. The maths involved in the technique can be very complex and off-putting, and many of those brought into contact with it are desperate for a simple introduction. This book fills that need, and already has a reputation for doing so. Arguments are presented in a technically acceptable yet sufficiently uncomplicated manner and text can readily be used in conjunction with other sources of information. This new edition incorporates fundamental help on the use of factor and cluster analysis programs with the statistical package SPSS. There are also links to an online data bank to enable students to carry out some analyses of their own as they read. This new material converts the present text into a user-friendly 'hands-on' text.