In this paper we present ethno-mining, a mixed methods approach drawing on techniques from ethnography and data mining. Ethno-mining is characterized by tight, iterative loops that integrate both the results and the processes of ethnographic and data mining techniques to interpret data. Ethno-mining provides two key benefits. First, it makes use of both qualitative and quantitative data (e.g. observations and sensor data) to study phenomena that are practically inaccessible through either data type alone. Second, it provides a means of interpreting that data which produces novel insights by exposing the biases inherent in either type of data alone. We present ethno-mining in the context of a study of mobility and laptop use in the home, discussing how findings from the study relate to the use of the method.