Background/Research question This doctoral thesis addresses the topic of Shared Decision Making, which is a specific decision making process in clinical practice. Within this process the patient and the physician make the decision about a diagnostic or therapeutic measure jointly. The exchange of information between the two parties (patient <-> physician) enhances the benefit, as it combines the personal preferences of the patient, reflecting his personality, interests, expectations and experiences, with the expertise of the physician, who can evaluate the clinical situation, employing medical advantages and avoiding disadvantages. However, Shared Decision Making is not seen as the ideal form of decision making in all clinical situations. Particularly in the case of emergency, when it might be necessary for the physician to make a quick and competent decision (Frosch & Kaplan, 1999). To date, the common thinking has been that medical decisions should be made using a primarily analytic-reflexive approach. In comparison to previous studies, in which facts and preferences about the decision procedure were collected, the author of this PhD thesis empirically investigated social norms on the appropriateness of Shared Decision Making by using the factorial survey to let members of the Academy for Ethics in Medicine (Akademie für Ethik in der Medizin e. V.; AEM) judge in which clinical situations which decision process is warranted. Method The utilized factorial survey includes seven factors (such as the reason for consultation, the number of therapeutic options, the adverse effects, the patient’s general desire to participate in medical decision-making), each with 2-3 levels (such as mild/severe disease, prevention). By using an experimental design these factors were consolidated into several short stories (vignettes) with different characteristics; each with its own specific treatment situation. By using a 5-point-scale the participants evaluated how the decision should be made in each described treatment situation. The questionnaire was delivered via post to all 500 members of the AEM. A total of 176 persons participated in the survey (rate of return: 35,2%). Through logistic regression it was possible to investigate the influence of the factors on the value judgments, their interactions and additional differences between groups. Results Results of this survey demonstrate that Shared Decision Making was the most frequently suggested response to the vignettes: 43,52% of all value judgments recommended a joint decision between patient and physician. By using regression analysis it was possible to identify several situational factors which significantly influence the evaluation of how treatment decisions should be made. The most relevant effect seemed to have the patient’s desire to participate in medical decision-making seemed. In addition, the majority of participants found Shared Decision Making most appropriate in the case of one’s own illness. Statistically, these judgments had the strongest significant influence on the evaluations of the vignettes: If the participants indicated to decide by themselves in the case of one’s own illness, they tended to judge towards patient’s decision. Discussion/Conclusion The investigated results of this study demonstrate the major role of Shared Decision Making in decisional procedures in medical practice. Furthermore the factorial survey allows to describe situations which present possibilities and limitations for decisions made jointly by the patient and the physician. For this purpose more research needs to be done. According to the results of this study the patient’s request to participate in the decision process seems to be particularly important to the question of which type of decisional procedure should be used. The optional autonomy should be noted and respected, which means that a patient’s autonomy should neither be attacked nor be forced (Edward & Elwyn, 2006). Another important result of this study is that social norms regarding the appropriateness of Shared Decision Making are most influenced by personal preferences. A social-normative judgment without individual inclinations was obviously not possible. In addition this PhD thesis demonstrates the importance of empirical collectable value judgments to answer at least part of a normative question. Further research addressing this discourse should follow.