This article describes the planning of a Nordic investigation of compu
lsory care, conducted by The Nordic Study Group Of Ethics, Law and Psy
chiatry. The purpose is to study the relationship between mental legis
lation, use of compulsion and perception of compulsion as experienced
by the patients. Before comparing the conditions in the different coun
tries, evaluation of the reliability and validity of public statistics
must be done. It is known that the formal registration of involuntary
commitment in the different Nordic countries does not cover the same
incidents. There are lots of methodological problems to deal with.