The classification follows from the paper Field Experiments by Harrison and List (2004 JEL). Field Experiments are classified into three categories, which are not always exclusive when trying to best fit an experiment.
Identical to convential lab experiments but with a non-standard subject pool.
Identical to artefacutal field experiments but with field context in either the commodity, task, or information set that the subjects use.
Identical to framed field experiments except that the subjects do not know they are participants in an experiment.