“a means for collecting information about both the context and content of the daily life of individuals…by asking individuals to provide written responses to both open- and closed-ended questions at several random points throughout each day of a normal week, whenever a signaling device prompts them to respond.”
Hektner, J. M., Schmidt, J. A., & Csikszentmihalyi, M. (2007). Experience sampling method: Measuring the quality of everyday life. Thousand Oaks, CA: Sage.