Ergodicity: the relationship between intra- and interindividual variation

Peter van Rijn PhD

Project: University of Amsterdam

Project running from: 1 June 2000 – 1 June 2004

Supervisors: Prof. dr P.C.M. Molenaar, prof. dr H.L.J. Van der Maas, dr C.V. Dolan

Summary:
The issue of how the structure of intraindividual variation is related to the structure of interindividual variation is of central concern to various fields of research, including mathematical statistics, psychometrics, developmental theory, and psychology at large. This relationship will be investigated at three levels: formal (starting from the so-called ergodicity theorems), synergetic (subjecting multi-case time series to longitudinal analysis), and empirical. The investigation will be mainly restricted to comparisons of factor models for time series (intraindividual variation) and longitudinal data (interindividual variation). The results will be of three kinds: 1) specification of the effects of various forms of nonergodicity on longitudinal factor analysis; 2) quantification of the bias in using interindividual structural models to predict intraindividual variation; and 3) the development of valid criteria to detect nonergodicity in (longitudinal) factor analysis.

Date of defence: 24 April 2008

Title of thesis: Categorical time series in psychological measurement