Here you find theses (BA/MA in psychology) that were supervised by PIDI Lab members. **PIDI Lab: UNDERSTAND & USE – Research in Pasteur’s Quadrant** The goals of the PIDI-Lab are to understand principles of health behavior by applying a judgment and decision-making and strategic-interaction perspective to infectious disease control – especially with regard to the vaccination decision and prudent use of antibiotics. We are interested in social and individual aspects of health and medical decision making. At the same time, we believe in the necessity to make research findings usable. That’s why members of the PIDI-Lab are also involved in creating online materials for health organizations (such as the ECDC) or in projects with authorities such as WHO/Euro or the Thuringian Ministry of Health. This combination of high understanding and high usability of research has been labeled “Pasteur’s Quadrant” (Stroke, 1997). We would like to follow this luminous tradition by striving for both high understanding and high usability to contribute to the attainment of public health goals.