JANET A. HARKNESS, PhD, is Director for Germany of the International Social Survey Program (ISSP), convenor and member of the ISSP methodology groups, and is internal coordinator of COMPASS, a five-country consortium of research institutes for European comparative social science survey research.

FONS J. R. Van de VIJVER, PhD, teaches cross-cultural psychology at Tilburg University, The Netherlands. He is Editor of the Journal of Cross-Cultural Psychology.

PETER Ph. MOHLER, PhD, is Director of ZUMA, member of the Board of Directors of GESIS, and a professor at Manheim University.