Which of the following is a challenge faced by both laboratory and field experiments?

The challenge of concerns regarding participant consent is relevant for both laboratory and field experiments due to the ethical considerations involved in conducting research that involves human subjects. In laboratory settings, researchers must ensure that participants fully understand the nature of the study and their rights, which includes obtaining informed consent prior to participation. Similarly, in field experiments, where the setting can be less controlled and more natural, gaining informed consent can be complicated, particularly if the research involves observations in public spaces or requires deception. This ethical requirement is crucial to protect the autonomy and well-being of participants, making it a universal challenge across different experimental settings.

On the other hand, the other challenges cited can vary significantly between laboratory and field experiments. For example, limited participant diversity might be more pronounced in laboratory settings where specific recruitment criteria can affect the demographic makeup of participants. Control is typically easier to establish in a lab due to the controlled environment, while field experiments often operate in unpredictable real-world settings. Lastly, the costs associated with implementation can differ widely depending on the context and scale of the study, and may not universally affect both types of experiments to the same extent.