In the first part of Pedulla’s (2016) study, he submitted two applications for each of 1,210 job openings, randomly varying key characteristics of applicants, and then tracked the callbacks. The characteristics of the two job applicants described in the applications for each opening differed systematically. In the second part of the study, Pedulla conducted an Internet-based survey of individuals who make actual hiring decisions, including human resources managers and associates as well as business executives, managers, and owners. What research design did Pedulla use in the first part of his study (and not in the second part)?
a. before-and-after design
b. ex post facto control group design
c. field experiment
d. time series design
e. nonequivalent control group design
