A Short Description of the Method

The increased availability of inexpensive sensors, tremendous processing capabilities (even in mobile devices), high-bandwidth wireless networks, and vast quantities of data storage have made it much more practical to continuously collect streams of low-level data about people and their environments. This approach enables researchers to compile detailed records of various contextual factors surrounding people’s interactions with their world. Their locations, physiological states, contact with other people, situated uses of devices, and other digital traces can potentially be recorded and analyzed. Each of these kinds of data can be collected at virtually any frequency, with or without participant knowledge or intervention, and for extended periods of time. Due to the automated nature of the method, a large number of samples can be gathered quickly and with relatively low overhead by the researchers during sessions in the fi eld. However, the degree of automation involved in this method requires a number of pragmatic and analytic considerations, beginning with careful experimental design to ensure appropriate sensor design, and including how the study is deployed, participant training, privacy safeguards, and data storage requirements. Sensor Data Streams