When you involve participants in your research, i.e. people you interview, observe, photograph, film, whose voice you record, who participate in surveys or tests, provide samples and so on, you need:
Informed consent means that participants should know and understand what they are participating in. Participants should also know that they have the right to withdraw their consent at any time.
There are ready-made data protection forms on the intranet that you can use. Read more on the intranet about data protection for students and instructions for data collection for bachelor's and master's thesis.