What is the guideline for compensating research participants?

Compensation for research participants is guided by the principle that it must not be coercive and should be proportional to the time and effort that participants invest in the study. This ensures that participants are not pressured into joining the research due to financial incentives, which helps to maintain the ethical integrity of the study. It also recognizes the value of the participants' contributions, compensating them fairly for their time and any discomfort or inconvenience they may experience while participating.

By ensuring that compensation is proportional, researchers can provide a fair incentive that reflects the nature and demands of the study, while simultaneously respecting the autonomy of individuals to make informed decisions about their participation. This approach aligns with ethical research standards that prioritize participant welfare and informed consent.

The other options are less aligned with these ethical considerations. For example, equal compensation across all participants may not account for varying levels of engagement or different levels of effort required by participants. Paying only at the end of the study may introduce coercion, as individuals might feel compelled to complete the study for financial reasons. Lastly, limiting compensation to transport costs might not adequately recognize the full scope of participant involvement and its inherent value.