Epistemology
The word "epistemology" is derived from the ancient Greek "epistēmē" meaning "knowledge" and the suffix "-logy", meaning "logical discourse" (derived from the Greek word "logos" meaning "discourse"). It is analogue to the German "Wissenschaftslehre" (literally, theory of science) which was introduced by philosophers Johann Fichte and Bernard Bolzano in the late 18th century. The word first appeared in English in 1847 as a translation of the German in New York's "Eclectic Magazine" review of a philosophical novel by German author Jean Paul:
Epistemic feedback
The term "epistemic feedback" is a form of feedback which refers to an interplay between what is being observed (or measured) and the result of the observation.
The concept can apply to a process to obtain information, where the process itself changes the information when being obtained. For example, instead of quietly asking customers for their opinions about food in a restaurant, making an announcement about food quality, as being tested in a survey, could cause cooks to focus on producing high-quality results. The concept can also apply to changing the method of observation, rather than affecting the data. For example, if after asking several customers about food, they noted the food as generally good or fair, then the questions might be changed to ask more specifically which food items were most/least liked. Hence, the interplay can alter either the observations, or the method of observation, or both.