Applied multivariate analysis, especially those methods concerned with graphical representations
Biplots: a series of research papers culminated in the book with David Hand, but the work continues. Recent developments include improvements in
representing scales on biplots axes for two-way tables and data matrices. A book, Understanding Biplots) written in collaboration with Niel LeRoux
(University of Stellenbosch) and Sugnet Lubbe, (University of Capetown) is in press with John Wiley, to be published in 2010. It deals with biplot
theory illustrated by applications drawn from many fields of application.
Procrustes problems. Procrustes problems originated with factor rotation but my interest is more concerned with matching two or more configurations.
Application areas are diverse including assessing responses of sensory test panels, general comparisons in multivariate analysis, rather more general
than common principal components analysis and shape analysis. The first monograph (in collaboration with Garmt Dijksterhuis University of Goningen) on
Procrustes Problems was published by Oxford University Press in 2004. A recent advance is a general treatment of missing values in Procrustes Analyses
and ongoing work is concerned with the links to Individual differences scaling.
Distance methods. A long-standing interest which encompasses the general area of multidimensional scaling. A book is planned in collaboration with
Michael Greenacre. Many statistical problems are concerned with the minimisation of a quadratic form under quadratic/linear constraints. Recent work
with Frank Critchley and Casper Albers (now University of Groningen) has unified the theory and algorithmic treatment of such problems.