Software is created by humans, for humans. For this reason, software engineering is - above all - a human activity. Acknowledging this fact, many researchers perform controlled experiments with human subjects to evaluate the performance and usability of novel approaches and software engineering tools. However, the intrinsically non-deterministic nature of humans introduces a number of threats to the validity of such experiments. One of them concerns how to record information without influencing the behavior of the subjects involved. Another one relates to providing means to assure the correctness of the gathered data, for further pristine analyses and replication. We present Biscuit, a tool that silently records relevant pieces of information regarding an experiment performed with human subjects. We present the main features and benefits of Biscuit by showcasing a controlled experiment of Gaucho, a next generation IDE. Based on our experience, we discuss the potential of Biscuit and outline future research in this direction. Copyright © 2012 ACM.