Field trials refer to a type of scientific experiment in which researchers conduct observations and collect data directly from their subjects, typically in real-world settings. This method is used to test hypotheses or theories about how certain variables may affect outcomes, by comparing results between groups that have been exposed to different conditions. Field trials can be conducted across a wide range of disciplines including agriculture, medicine, psychology and education among others. The goal of these studies is often to determine the effectiveness of an intervention or treatment in real-world situations, as opposed to controlled laboratory settings.