Revealing Hidden Context: Improving Mental Models of Personal Firewall Users

The Windows Vista personal firewall provides its diverse users with a basic interface that hides many operational details. However, concealing the impact of network context on the security state of the firewall may result in users developing an incorrect mental model of the protection provided by the firewall. We present a study of participants' mental models of Vista Firewall (VF). We investigated changes to those mental models and their understanding of the firewall's settings after working with both the VF basic interface and our prototype. Our prototype was designed to support development of a more contextually complete mental model through inclusion of network location and connection information. We found that participants produced richer mental models after using the prototype than when working with the VF basic interface; they were also significantly more accurate in their understanding of the configuration of the firewall. Based on our results, we discuss methods of improving user understanding of underlying system states by revealing hidden context, while considering the tension between complexity of the interface and security of the system