> ... A similar sentiment was expressed by Marvin Minsky: "Unfortunately, the strategies most popular among AI researchers in the 1980s have come to a dead end," said Minsky. So-called “expert systems,” which emulated human expertise within tightly defined subject areas like law and medicine, could match users’ queries to relevant diagnoses, papers and abstracts, yet they could not learn concepts that most children know by the time they are 3 years old. “For each different kind of problem,” said Minsky, “the construction of expert systems had to start all over again, because they didn’t accumulate common-sense knowledge.” Only one researcher has committed himself to the colossal task of building a comprehensive common-sense reasoning system, according to Minsky. Douglas Lenat, through his Cyc project, has directed the line-by-line entry of more than 1 million rules into a commonsense knowledge base."