The present set of notes grew out of our interest in the study of
statistical transformation models, in particular exponential transfor-
mation models. The latter class comprises as special cases all fully
tractable models for mUltivariate normal observations. The theory of
decomposition and invariance of measures provides essential tools for
the study of transformation models. While the major aspects of that
theory are treated in a number of mathematical monographs, mostly as
part of much broader contexts, we have found no single account in the
literature which is sufficiently comprehensive for statistical pur-
poses. This volume aims to fill the gap and to indicate the usefulness
of measure decomposition and invariance theory for the methodology of
statistical transformation models. In the course of the work with these
notes we have benefitted much from discussions with steen Arne
Andersson, J0rgen Hoffmann-J0rgensen and J0rgen Granfeldt Petersen. We
are also very indebted to Jette Ham- borg and Oddbj0rg Wethelund for
their eminent secretarial assistance.