Studies finding that a treatment has no noticeable effects are sometimes greeted with statements that "more research is needed" by those convinced that the treatment is effective, but the effect has not yet been found.[4] Since even the largest study can never rule out an infinitesimally small effect, an effect can only ever be shown to be insignificant, not non-existent.[5] Similarly, Trish Greenhalgh, Professor of Primary Care Health Sciences at the University of Oxford, argues that FRIN is often used as a way in which a "[l]ack of hard evidence to support the original hypothesis gets reframed as evidence that investment efforts need to be redoubled", and a way to avoid upsetting hopes and vested interests. She has also described FRIN as "an indicator that serious scholarly thinking on the topic has ceased", saying that "it is almost never the only logical conclusion that can be drawn from a set of negative, ambiguous, incomplete or contradictory data."[6]