Introduction to the Special Issue: Innovations and Current Challenges in Experimental Methods

Political science has increasingly embraced the experimental method to establish causal relationships suggested by theories and observational studies—from experiments’ traditional sub-disciplinary home, political psychology, to international relations. The most frequently voiced concern with experiments, qualms about their external validity in terms of sample, has been well documented and addressed (Coppock, Leeper, and Mullinix 2018; Krupnikov and Levine 2014; Krupnikov, Nam, and Style 2021; Lupton 2019; McDermott 2011; Mutz 2021). 1 Experiments uniquely provide scholars with the internal validity necessary to confidently identify causal effects, and issues with specific experiments tend to arise through errors of application by individual scholars rather than through any broad problems with the methodology.