This contribution presents the rationale for the other chapters in this book, to which it serves as introduction. We discuss sequentially: our emphasis on tilapia (Oreochromis spp., Fam. Cichlidae), modelling of pond aquaculture, exploratory and con­ firmatory methods for multivariate analysis, the relationships between multiple regression and analysis of' variance and the rationale for sharing and analyzing "old", public domain data, all with emphasis on tropical/subtropical aquaculture systems.