Applied multivariate statistics has grown into a research area of almost unlimited potential in the natural sciences. The methods introduced in this book can successfully reduce masses of data to manageable and interpretable form. The authors give special attention to methods of robust estimation and the identification of atypical and influential observations. This textbook aims to introduce students of the natural sciences to the powerful technique of factor analysis and to provide them with the background necessary to be able to undertake analyses on their own. The authors explain new concepts in detail, and provide mathematical background where needed.