Abstract—The Ubicorder is a mobile, location and orientation aware device for browsing and interacting with real-time sensor network data. In addition to browsing data, the Ubicorder also provides a graphical user interface (GUI) that users can use to define inference rules. These inference rules detect sensor data patterns, and translate them to higher-order events. Rules can also be recursively combined to form an expressive and robust vocabulary for detecting real-world phenomena, thus enabling users to script higher level and relevant responses to distributed sensor stimuli. The Ubicorder’s mobile, handheld form-factor enables users to easily bring the device to the phenomena of interest, hence simultaneously observe or cause real-world stimuli and manipulate in-situ the event detection rules easily using its graphical interface. In a first-use user study, participants without any prior sensor network experience rated the Ubicorder highly for its usefulness and usability when interacting with a sensor network. I.