A fieldworker is the person who goes out and does that kind of study — knocking on doors with a survey, sitting with a family to see how they live, walking a forest and counting birds. Though actually, the name looks as if it might mean the study itself; the study is fieldwork, and the fieldworker is the human being doing it. You meet the word in science, in charity work, and in news about research. It is a plain, slightly formal job word, not a dramatic one.

田野調查員、實地訪員（去做田野調查的人，不是調查本身）。