Overcommitment was solely assessed
by a questionnaire (cf. Matschinger, Siegrist, Siegrist, &
Dittmann, 1986). Subsequently, a questionnaire was
developed to measure all components of the ERI Model,
i.e., effort, reward and overcommitment. The introduction
of this so-called ERI Questionnaire (ERI-Q;
(Siegrist & Peter, 1996a) led to a predominant use of
questionnaires to test the ERI Model.