With the expanding popularity of "brand-image" and market segmentation studies, the use of statistical data processing methods has increased. In particular, one can note an increase in the application of multivariate analysis techniques to quantitative investigations of the relationships between consumer typologies, attitudes and purchasing behaviour. In this paper, we discuss various problems associated with the use of "packaged" computer programs designed to effect the required multivariate analyses. Although these programs can and often do provide adequate results, it should be remembered that each set of survey data has unique properties. In some cases, these properties can jeopardise the validity of the whole analysis. The techniques we discuss are: a) Principal component based analyses. b) "Cluster-analysis" type techniques. The paper falls into two sections.