Over the last forty years quantitative structure-property relationships (QSPR) have developed into a major method of chemical research. In the course of this development, the field has suffered from fragmentation. Thus, those working in physical organic chemistry form one constituency, those in organic chemistry another, spectroscopists constitute a third, medicinal and agricultural chemists a fourth, environmental chemists are yet another, and so on. There is nevertheless a common thread which runs through these widely diverse areas: the basic principles, parameterization, and methodology are the same or similar throughout.The object of this series is to provide interesting and timely reviews covering all aspects of the field. It is our hope that this will encourage the transfer of new methods, techniques and parameterizations from the field in which they were developed to other areas that can make good use of them.