A temporary fortification in the field
The collection of raw data, in the field
A temporary fortification built by troops in the field; a defensive earthwork in the field.
The collection of raw data in the field, field research, field study, field studies.
Work done out in the fields as opposed to that done elsewhere on the farm (e.g., barn, house, outbuildings, office).
Work done out in the real world rather than in controlled conditions