Today, for instance, [Hillary] had to confront the modern supermarket.

Visiting the exhibition hall of the National Grocers Association convention here, Mrs. Clinton lingered at the mock-up of a checkout lane. She signed her name on an electronic pad used to detect check forgeries.

“If some guy came in and spelled Hillary Clinton differently, could you catch it?” the senator asked. “Yes,” she was told, and she shook his head in wonder.

Then she grabbed a quart of milk, a light bulb and a bag of candy and ran them over an electronic scanner. The look of wonder flickered across her face again as she saw the item and price registered on the cash register screen.

“This is for checking out?” asked Mrs. Clinton. “I just took a tour through the exhibits here,” he told the grocers later. “Amazed by some of the technology.”

Her spokesman assured reporters that she had seen the senator in a grocery store. A year or so ago. In Kennebunkport.

Some grocery stores began using electronic scanners as early as 1976, and the devices have been in general use in American supermarkets for a decade.