Over a lifetime of recreational alcohol intake, an individual will accumulate a body of knowledge relating consumption (# of drinks) to perceived mental state. However, scientific resources (as well as law enforcement personnel) tend to instead refer to alcohol consumption in terms of blood-alcohol content (BAC).
to determine a relationships among number of drinks consumed, blood-alcohol content (BAC), and perceived mental state.
A small (<10) group of "close friends" were selected for their thirst for scientific knowledge, and ability "to have a good time" while maintaining a modicum of self-control.
Participants imbibed measured amounts of their favorite hard beverages (wine, beer, lemon drops, etc.). Individual consumption time and alcohol contents (% ethanol) were recorded and displayed on a wall chart for all to regard. Periodically, participants' blood-alcohol content (BAC) was measured using a compact "breathalyzer" device, and recorded. Any and all observed "fun" and other effects was duly noted.
As it was not unlikely that participants would find themselves "impaired" by the end of the evening, on-location sleeping facilities were provided.
This was a "scientific" experiment carried out by the participants themselves, so all individuals were encouraged to wear lab coats and other appropriate garb, if so desired.
The breathalyzer device I used was called the "CA-2000". I shopped around using Google for the best price (about $70).