Dr. Choi’s team recently demonstrated Engkey’s interactions with four sixth graders from Seoul who had not met the robot. Engkey tracked a student around the room, wheeling to a stop a foot away, and extended a greeting in a synthesized female voice. (Although a male voice is also available, Dr. Choi says the female model seems more effective in teaching. ) She then led the boy to a shelf stacked with plastic fruit.  “How can I help you today?” Engkey said.  “Do you have any fruits on sale?” the student said.  “Wow! Very good!” Engkey exulted. She sounded a fanfare, spun and raised her left arm for a high-five. A screen on her chest showed stars grading the student.  “It’s cool — a machine hearing and responding to me,” said Yang Ui-ryeol. “There seems to be a life inside it.”  Still, Engkey has a long way to go to fulfill her creators’ dream. The robot can help students practice only scripted conversations and is at a loss if a student veers off script, as Yang did during the demonstration.  “I love you,” the boy said to appease Engkey after he was chastised for a bad pronunciation. Engkey would have none of it; it was not in her programmed script.  “You need to work on your accent,” the robot repeated.  When Yang said, “I don’t like apples” instead of “I love apples,” as he was supposed to, Engkey froze. The boy patted her and said, “Hello, are you alive or dead?”  The trials and errors at the Korea Institute, a wooded top-security compound for the country’s best scientific minds, represent South Korea’s ambitious robotic dreams.  Last month, it announced a trial service for 11 types of intelligent robots this year. They include “kiosk robots” to roam amusement parks selling tickets, and “robo soldiers” that will man part of the 155-mile border with North Korea with a never-sleeping camera eye, night vision and lethal fire power.  But the most notable step was this country’s plans to use robots as teaching aids. In February, the Education Ministry began deploying hundreds of them as part of a plan to equip all the nation’s 8,400 kindergartens with robots by 2013.  One type of robot, toddler-size with a domed head and boxlike body on wheels, takes attendance, reads fairy tales and sings songs with children. A smaller puppy robot helps leads gymnastics and flashes red eyes if touched too roughly.  Even though they are little more than fancy toys, experts say, these robots prepare children for a fast-approaching robotic future.  Early this year, when the institute did an experimental run of Engkey in Masan on the south coast, there was a mad rush among children to be selected for the program, said Kim Bo-yeong, an English teacher.  “They all loved robots. They get shy before a foreign native speaker, afraid to make mistakes,” Ms. Kim said. “But they find robots much easier to talk to.”  An independent evaluator of the trial noticed that Engkey required the constant presence of a technical operator. “Engkey has a long way to go if it wants to avoid becoming an expensive yet ignored heap of scrap metal at the corner of the classroom,” said Ban Jae-chun, an education professor at Chungnam National University.  Dr. Choi knows the challenge. After tests in more schools this winter, he hopes to commercialize Engkey and to reduce the price, currently $24,000 to $32,000, to below $8,000.  Dr. Choi said his team was racing to improve the robot’s ability to recognize students and to discern and respond to a student’s voice amid noise. It is also cramming Engkey with more conversational scenarios.  For now, though, Engkey’s limits quickly become apparent. Hahn Yesle, who participated in the recent demonstration, said: “Engkey is fun. But she is not human. Repeating the same dialogue is what she does. I wish she would become more expressive and responsive, like a human teacher.”  A version of this article appears in print on July 11, 2010, on Page A19 of the New York edition with the headline: Exacting Teaching Machine Sticks to the Script in South Korea. Order Reprints| Today's Paper|Subscribe
The country, known for its enthusiasm for technology, is “hiring” hundreds of robots as teacher aides and, and is experimenting with robots that would teach English.