 Suppose that our theory tells us that we will find a particle in an energy range. And suppose we find a significant signal in a section of that very range. Perhaps we should keep looking elsewhere within the range to make sure it is not another particle altogether we have discovered. It may be a particle that left other undetected traces in the range that our theory does not predict, along with the trace we found. The question is to what extent we should look elsewhere before we reach a satisfying level of certainty that it is the predicted particle we have discovered.