In many surveys, field procedures address nonresponse with a combination of callback efforts and changes in the mode of data collection. To analyze the resulting data, one generally needs to account for the relevant features of the underlying population, the sample design, and the nonresponse follow-up plan. This paper suggests a relatively simple approach based on random assignment of sample units to distinct groups. Each group receives different treatments defined by, e.g., varying numbers of callbacks, different contact and interview modes, different response incentives, and different levels of interviewer training. Some properties of the proposed methods are evaluated through a simulation study.