Previous studies on the construct validity of assessment centres have gener
ally produced puzzling results. The premise of this study is that these pri
or studies were relatively one-sided. Actually, most previous studies were
field studies, which typically used the multitrait-multimethod approach to
distinguish between two sources of variance (i.e., exercises and dimensions
). Therefore, this study aims to shed light on the issue of assessment cent
re construct validity by addressing substantive and methodological concerns
inherent in previous research. In this study, 85 industrial and organizati
onal psychology students and 39 managers rated videotaped assessment centre
candidates in three exercises on six dimensions. Results from generalizabi
lity analyses showed that assessors' ratings were relatively veridical. In
addition, when assessors rated candidates whose performances varied across
dimensions and whose performances were relatively consistent across exercis
es, they were reasonably able to differentiate among the Various dimensions
. They also rated such candidate profiles similarly on the various dimensio
ns across exercises. When assessors rated a candidate profile without clear
performance fluctuations across dimensions, distinctions about dimensions
were more blurred. Results from student and managerial assessors were simil
ar, although managers distinguished somewhat less between the various dimen
sions. The research and practical implications of these findings are discus
sed. Copyright (C) 2001 John Wiley & Sons, Ltd.