I suspect it will be - most of medicine uses the idea of 'reference ranges' to establish normal physiological state. The reference range is simply the range of

I suspect it will be - most of medicine uses the idea of 'reference ranges' to establish normal physiological state. The reference range is simply the range of observed states of whatever characteristic is being measured. Here, I would be interested in a study that maps caffeine doses to changes in various characteristics such as alertness/acuity and latency between periods of falling asleep.