Professor Judea Pearl has won his second Classic AI Paper Award given by the AI Journal for his paper “Temporal Constraint Networks”  with coauthors (then UCLA students) Rina Dechter and Itay Meiri. (

Only papers that are “exceptional in their significance and impact” and were published at least 15 calendar years ago in the AI Journal are eligible for the AIJ Classic Paper Award. (

In 1990, Pearl, Dechter, and Meiri offered a polynomial time algorithm in their paper to solve a simple problem: finding one or more scenarios consistent with two specific data sets (possible times certain events may occur and the relationships between those events). This algorithm had a significant impact on subsequent work in automated planning. Rina Dechter, now Distinguished Professor at UC Irvine, then a PhD student of Pearl—>usually, people are referred to by their last name in articles because referring to a person by their first name assumes a familiarity that may not be present for either the author or the reader. It’s more respectful., followed this research with a comprehensive textbook on “Constraint Processing” (Morgan Kaufmann 2003).

This is Pearl’s second Classic Paper Award.  The first one in 2015 “introduced Bayesian networks and the distributed, linear-time, message-passing algorithm for belief propagation in singly-connected networks.” ( This is UCLA’s third Classic Paper. (In 2016, Rich Korf received the Classic AI Paper Award for “Real-time heuristic search.” The citation describes Korf’s paper as the “seminal paper in real-time heuristic search over the basic state model considered in AI.”)