Willem Jan Heiser (born 19 January 1949) is a Dutch social scientist who was Professor of Psychology, Statistical Methods and Data Theory at the Leiden University between 1989 and 2014.
[2] He received his PhD in 1981 from the Leiden University with a thesis entitled "Unfolding analysis of proximity data" advised by John van de Geer and Jan de Leeuw.
Back at the University of Leiden in 1982 he joined the Department of Data Theory, were in April 1989 he was appointed Professor of Psychology & Statistics.
Heiser's research interests are in the fields of "multivariate categorical data using multidimensional scaling and classification techniques... advanced clustering and classification methodology for FMRI data.
"[1] At his farewell speech on 31 January 2014, Heiser was knighted in the Order of the Dutch Lion by the mayor of Leiden, Henri Lenferink.