Investigating Data with Andrews Plots

Most data that are collected are multivariate in nature, and much of them can be regarded as continuous. In the initial stages of analysis, graphic displays can be used to explore the data, but for multivariate data, traditional histograms or two- or three-dimensional scatter plots may miss complex relationships that exist in the data set. A number of methods for graphically displaying multivariate data have been suggested. However, these are not generally available in major statistical packages and are thus largely not used by researchers. One of the most appealing methods is that of Andrews Plots. This article discusses the potential uses of Andrews Plots and makes them accessible to users through the production of a freely available add-in for Microsoft Excel. The use of Andrews Plots is demonstrated by using data from the 2001 Parliamentary General Election in the United Kingdom.