Published online by Cambridge University Press: 14 October 2019
Experiments should be designed to facilitate the detection of experimental measurement error. To this end, we advocate the implementation of identical experimental protocols employing diverse experimental modes. We suggest iterative nonparametric estimation techniques for assessing the magnitude of heterogeneous treatment effects across these modes. And we propose two diagnostic strategies—measurement metrics embedded in experiments, and measurement experiments—that help assess whether any observed heterogeneity reflects experimental measurement error. To illustrate our argument, first we conduct and analyze results from four identical interactive experiments: in the lab; online with subjects from the CESS lab subject pool; online with an online subject pool; and online with MTurk workers. Second, we implement a measurement experiment in India with CESS Online subjects and MTurk workers.
Authors’ note: We would like to acknowledge the contributions of the Nuffield College Centre for Experimental Social Sciences postdocs who were instrumental in helping design and implement the experiments reported on in the manuscript—these include, John Jensenius III, Aki Matsuo, Sonke Ehret, Mauricio Lopez, Hector Solaz, Wojtek Przepiorka, David Klinowski, Sonja Vogt, and Amma Parin. We have also benefited from the very helpful comments from colleagues including Vera Troeger, Thomas Pluemper, Dominik Duell, Luke Keele, and Mats Ahrenshop. And thanks to the Political Analysis reviewers, editor and editorial team who were extremely helpful. Of course we assume responsibility for all of the shortcomings of the design and analysis. All replication materials are available from the Political Analysis Dataverse, doi.org/10.7910/DVN/F0GMX1 (Duch et al.2019).
Contributing Editor: Jeff Gill