The interpretation of collective agreements exists in the tension between the interpretation of laws and the interpretation of legal transactions. The statutory effect suggests applying the rules of legal interpretation to collective agreements. The contractual origin implies a transactional interpretation. A corresponding conflict arises in the further development of collective agreements. Which of these options is the correct one, or whether a third way of interpreting collective agreements must be pursued, can be understood through the interpretation of laws and legal transactions. A comparison of the respective interpretative methods highlights differences and similarities. The author demonstrates that in interpretation, one can choose between determining content or setting content. In all three interpretative subjects, determining content takes precedence.