When participants attend the "Erweiterte Erste Hilfe für Studierende der Humanmedizin" they will receive a short introduction about the study. The investigators will invite all first year students to participate in the study. As the study is voluntarily, participants need to sign a written informed consent. After that, the investigators will randomize the students to either group A or Group B. Group A will train their technical CPR-skills with supervision by a tutor (either general practitioner or medical student, all trained in CPR teaching) and group B will train without supervision. The participants in group B will not be allowed to communicate with each other during the training and they will be prevented from watching each other. The training will take about 30 minutes for each group. Directly after the training each group will be tested and the printed report form from the Laerdal Skill Reporter will be obtained for each participant. In the test the students will perform CPR in a simulated scenario as a first responder. The scenario is: "A male person has collapsed at the railway station." The participant should start CPR as learned in the training. During the CPR a departmental research fellow will observe the study participants and record BLS/AED actions on a scoring sheet.