The subjects were the male patrons of predominantly English Montreal bars. The sample consisted of 38 males with a mean age of 24.4 and a range of 19 to 34. The mean BAL, estimated using the formula developed by Watson et al., , was .061. The mean SES of the subjects and their fathers were near the mid-point of the Blishen and McRoberts  scale. All subjects were drinking in male groups of an average size of 2.63 people.
Surveyors carried clipboards with the McGill insignia and “Alcohol Research Group” printed on the cover. The questionnaire asked what beverage the subject was drinking at the time, what his usual beverage was, how much beer, wine, and liquor he had consumed that evening, how intoxicated he felt, the time of his first drink, and questions concerning height, weight, age, and the subject’s and his father’s occupation. Confederates were equipped with Aiwa TP-MIO microcassette recorders and Aiwa tie-clip microphones. The female confederates wore their microphones as jewelry and the males wore they’re clipped under sweaters. They have dressed appropriately for the bars visited. The conversations were rerecorded in a random order on a reel to reel tape recorder using a graphic equalizer to increase the voice to noise ratio. Raters listened on stereo headphones to the tapes played back over the same tape recorder, amplified by an integrated amplifier. The interactions were also transcribed and typed for the raters to read.
Bars were randomly selected from a list of currently licensed premises provided by La Regie des Permis d’Alcohol du Quebec. A bar was excluded if it had any of the following characteristics: only male patrons served only non-distilled beverages, nude dancers, a gay bar, primarily a restaurant, table service only, or a clientele predominately over 35. Bars were visited on a Thursday, Friday, or Saturday evening between 9:00 and 2:00, as these are the times when a disproportionately high level of alcohol-related aggression occurs [Gersen and Preston, 1979. Wolfgang, 1958]. The research team divided into two randomly determined pairs: a pair of surveyors and a pair of confederates with a male and a female in each pair.