The most surprising concept that I learned in the interview with Jill Tarter was that the system that they use to study extraterrestrial life is simply the study of feedback signals in space to see if there is any other form of technology in space. The system they use does not actually predict anything but just tries to eliminate the uncertainty. The predictive system is based on analytics and they compare it to prior studies to see if whatever they discovered is worth following.
A question that I would've followed up with would be why do we make the assumption that other plants have technological advancements to create a potential signal that would indicate life? What if there is life on other planets but they have not had the ability to develop traceable technology? How can these systems account for such?