fieldwork

Từ điển Oxford Advanced Learner 8th

field·work BrE [ˈfiːldwɜːk] NAmE [ˈfiːldwɜːrk] noun uncountable
research or study that is done in the real world rather than in a library or laboratory
•Most of the fieldwork was carried out in Italy.
Derived Word: ↑fieldworker

Example Bank:
•extensive fieldwork on chimpanzees