Regier DA, Sicsic J, Watson V. Choice certainty and deliberative thinking in discrete choice experiments. A theoretical and empirical investigation. J Econ Behav Organ. 2019 Aug;164:235-55. doi: 10.1016/j.jebo.2019.05.031
Reed (Earnshaw) SJ, Reed JH. The use of statistical quality control charts in monitoring interviewers. Proceedings of the Survey Research Methods Section, American Statistical Association. 1997 Jan;893-8.