Well, as the linked article says, he basically coined the term "Bayesian network" and developed much of the underlying theory (e.g., which kind of independencie

Well, as the linked article says, he basically coined the term "Bayesian network" and developed much of the underlying theory (e.g., which kind of independencies it can/cannot capture). This was arguably a crucial step for many areas of modern AI in terms of dealing with uncertainty, cf. the full ACM press release: http://www.acm.org/press-room/news-releases/2012/turing-award-11/ http://www.acm.org/press-room/news-releases/2012/turing-awar... He is also credited with first describing the ever-popular belief propagation algorithm for approximate reasoning in Bayesian networks and graphical models in general. Edit -- I found this to be a nice, short exposition: http://ftp.cs.ucla.edu/pub/stat_ser/r368.pdf http://ftp.cs.ucla.edu/pub/stat_ser/r368.pdf