Ethnography is a scientific research strategy often used in social science. It is often employed for gathering empirical data on human societies and cultures. Data collection is often done through participant observation, interviews, questionnaires, etc. Ethnography aims to describe the nature of those who are studied (i.e. to describe a people, an ethnos) through writing.
The system can send surveys (on a daily/weekly basis) - for users to complete the same survey. This can be very useful in the case of longitudinal research, where there is continuous long-term study.