In this Chapter, we define, categorize and describe how Lab-in-the-Field experiments answer questions that concern specific subject populations or particular contexts, concentrating on economics-style experiments in particular. We discuss how to identify questions that require Lab-in-the-Field methods. We then explain how to develop a Lab-in-the-Field experiment highlighting key features of lab and field experiments, and outline the proper usage of pilots in the lab before moving to the field. We next discuss the main dimensions for implementing Lab-in-the-Field experiments: recruitment, research assistants, literacy of the population, payoffs, community involvement, debriefings, longitudinal surveys, power estimations, etc. We classify studies based on these dimensions. Lastly, we note that the research question should be the most important component driving the choice of subject population.