In a hardening survey climate, decreasing probability of making contact with sampled individuals puts a lot of strain on survey operations – especially in interviewer administered surveys. For example, if the probability of contact at the first contact attempt changes (i.e. decreases) there will be more cases to follow up at the second call attempt and so on. As the probability of contact decreases, the workload for survey operations increases.

For each contact attempt you can specify a cost and see how many contact attempts the data collection budget can afford. The total number of contact attempts has then to be transformed into a data collection strategy where the contact attempts are “assigned” to each sample unit. For example one could divide the resources (contact attempts) equally between all sample units (that is treat all cases equally). Another strategy is to allocate the contact attempts differently between subgroups in the sample, i.e. allocate more contact attempts to sample units that are prioritized by some criterion (for example balance of the response set).

The aim of the data collection strategy might, for example, be to reduce nonresponse bias or cost. There is likely a tradeoff between these aims. In the seminar these issues will be discussed and some examples of applications to the Swedish Labour Force Survey will be given.