This research by Prof. Kevin A. Harrigan at the University of Waterloo examines characteristics of Ontario slots and what the implications are for problem gamblers, including analysis of the probability accounting reports (or PAR sheets) to see how the games are designed. One of their key findings include: “Bonus modes are highly salient environments associated with wins that are in the view of the gambler a very good place to be. Because entering these arousing and highly rewarding bonus environments is rare, only those who gamble frequently will become classically conditioned to these environments and experience the combined effects of operant and classical conditioning – a situation that could preferentially target problem gamblers.”

PAR Sheets, Probabilities and Slot Machine Play – Implications for Problem and Non-Problem Gambling