Minerva isn't the typical tour guide. She's 4 feet high, shaped like a tank and you get her to talk by touching a screen behind her neck - or what would be her neck if she weren't made of plastic and aluminum.

Even so, her red mouth can smile and she can talk about an exhibit."I need to get through," she says, loudly but gently, as she maneuvers past little boys jumping up and down and making faces in front of her.

Minerva is working through Sept. 5 at the National Museum of American History, thanks to Carnegie Mellon University.

Her onboard computer has developed a map by which she goes through an exhibit called "Material World," using laser beams and collision-avoidance sonar to maneuver around groups of visitors and other obstacles.

She leads five tours that cover three to five items each. They deal largely with robots and how they are made.

Minerva, named for the Roman goddess of wisdom, was developed by a team under 31-year-old Sebastian Thrun, assistant professor of computer science at Carnegie Mellon. He was also responsible for a less sophisticated ancestor called Rhino at the Deutsches Museum in Bonn, Germany, last year.

Thrun sees possible practical developments from Minerva that go beyond museum exhibits, to janitorial services, shopping malls and health care.

"You could go to a robot in a shopping mall and punch in `I need a pair of socks,' and the robot would lead you where you had to go," Thrun said, closely watching a computer screen that would show him if Minerva got into any trouble. She didn't.

Grinell More, president of Real World Interface of Jaffrey, N.H., which put Minerva together, said his company hopes to have something to offer shopping malls in a year or two. He estimated each robot would cost $10,000 to $50,000, depending on its task.

"It really would have to be a chain of shopping malls to get the right financial base," More said.

Robots are already available for cleaning offices, Thrun noted, but they cost more than human labor. He hopes they could one day do simple domestic tasks to help elderly people stay in their homes, rather than go to nursing homes.

The exhibit, "Material World," was designed to show how materials - natural and man-made - affect the way America has de-veloped. It includes more than 400 objects from wooden spinning wheels to an anvil to a "one-armed bandit."