 Among the critics of McCarthy 's approach were his colleagues across the country at MIT . Marvin Minsky , Seymour Papert and Roger Schank were trying to solve problems like " story understanding " and " object recognition " that required a machine to think like a person . In order to use ordinary concepts like " chair " or " restaurant " they had to make all the same <unk> assumptions that people normally made . Unfortunately , <unk> concepts like these are hard to represent in logic . Gerald Sussman observed that " using precise language to describe essentially <unk> concepts doesn 't make them any more precise . " Schank described their " anti @-@ logic " approaches as " <unk> " , as opposed to the " <unk> " <unk> used by McCarthy , Kowalski , Feigenbaum , Newell and Simon . 
