Would I Lie to You - Would You Notice?

The quantified self-paradigm is well established. Its main purpose is to use numbers from sensors to derive self-knowledge. The massive availability of persuasive technology to monitor physiological parameters of humans made the paradigm available to a tremendous number of people. A multitude of different hard- and software platforms are available at the market. They all have different properties at different levels of quality. All in common is their promise to provide accurate and precise data about the humans' physiological condition and performed activities. Basically, they all provide a tool to make people aware of formerly hidden, non-observable, body signals. The gained awareness can then be used by people to e.g. improve their health or fitness level. In this work, we emphasize the perception of the gathered sensory data by the people. We focus on the question of how the trustworthiness of the recorded and presented data is perceived by people. As a fact, non-credible data can be understood by the user as being trustworthy and can have a negative impact on users' behavior. This can be especially critical for human's health in the fitness and medical application domain. It is of high importance to understand how people perceive and correlate their intrinsic body feelings with the data collected and presented by a mobile smart device like a smart watch or a fitness tracker.