The documentation and collection of descriptive details of events in nature such as amounts, sizes, colors, smell , behavior, texture e.t.c are all categorized as field studies.
It involves the gathering of raw data outside a laboratory.
Often times, based on the needs of an experiment, it is desirable to corroborate laboratory studies with field evidences.
The approach in gathering such data varies from discipline to discipline.
Most field sampling are usually done in an uncontrolled environment.