What is BOS?
Best Object Scaling (BOS) aims to measure the relative preference among a set of objects, features, statements, attributes, brands, concepts, policies, processes, etc. through a series of explicit trade-offs that respondents make using an underlying subjective scale.

One of the most challenging aspects of conducting telephone (CATI) surveys is reaching people when they are willing and able to receive a phone call. The proliferation of ‘scam’ calling (and telecom apps that flag calls that are unknown) has made consumers less likely to pick up their phone.  (Reference