  Monitoring techniques can extract accurate data about the behavior of
software systems. When used in the field, they can reveal how applications
behave in real-world contexts and how programs are actually exercised by their
users. Nevertheless, since monitoring might need significant storage and
computational resources, it may interfere with users activities degrading the
quality of the user experience. While the impact of monitoring has been
typically studied by measuring the overhead that it may introduce in a
monitored application, there is little knowledge about how monitoring solutions
may actually impact on the user experience and to what extent users may
recognize their presence. In this paper, we present our investigation on how
collecting data in the field may impact the quality of the user experience. Our
initial results show that non-trivial overhead can be tolerated by users,
depending on the kind of activity that is performed. This opens interesting
opportunities for research in monitoring solutions, which could be designed to
opportunistically
