Data quality is usually associated with the quality of data values. Bu
t even perfectly correct data values are of little use if they are bas
ed on a deficient data model. The purpose of this paper is to present
and discuss a list of characteristics (dimensions) that are crucial fo
r data model quality. We single out 14 quality dimensions, organized i
nto six categories: content, scope, level of detail, composition, cons
istency, and reaction to change. Two types of correlation among dimens
ions called ''reinforcements'' and ''tradeoffs'' are recognized and di
scussed as well.