Before conducting an experiment with human subjects, researchers much consider a number of important ethical and regulatory constraints. This chapter reviews the leading ethical concerns that arise in the context of human subjects research in general and experimental research in particular. These ethical concerns have also set in motion regulations, such as The Common Rule, that researchers must follow before launching a study. The chapter concludes by discussing other professional norms, such as research transparency.

Publication bias and p-hacking are threats to the scientific credibility of experiments. If positive results are more likely to be published than null results conditional on the quality of the study design, then effect sizes in meta-analyses will be inflated and false positives will be more likely. Publication bias also has other corrosive effects as it creates incentives to engage in questionable research practices such as p-hacking. How can these issues be addressed such that the credibility of experiments is improved in political science? This chapter discusses seven specific solutions, which can be enforced by both formal institutions and informal norms.