His family had coached him and prepared him and advised him and comforted him. But when 4-year-old Robert Belli first confronted officialdom at Children's Hospital on Sunday afternoon, he froze.

"Do you know why you're here, Robert?" the attendant at the information booth in the lobby asked him.

Robert shook his head.

His 7-year-old brother John groaned, the way older brothers will. His parents, David and Cathey smiled. Finally, Robert remembered.

"Oh, yeah," he said. "I gonna get a operation."

It will be performed tomorrow at 11 a.m., to be exact, and it is expected to be routine. Robert Victor Belli will have surgery on a left-side hernia. He is expected to be out of the operating room within two or three hours, home that same evening and up and about the next day.

But the measure of any hospital is how well it does with the day-in-day-out procedures, not just the glamor and glitter of open-heart surgery or rescues from death's door. The very fact that Robert's surgery is expected to be so uneventful makes him a good patient through which to look at Children's. So with the consent of his parents, that's what we're going to do.

In this morning's column, and a series of others, we'll be taking a look at how well Children's does the job for Robert Belli. I was along for the ride Sunday as Robert and family were given an orientation tour of the hospital by volunteer Sibyl Gant. I'll be there Friday, sitting in the parents' waiting room with David and Cathey. And I'll drop in at the Bellis' home in Northwest a few days later to see how the experience seems to all of them in retrospect.

For the blond dynamo his family calls Rob, Sunday was more like a day at the circus than a run-through for surgery.

There was a movie of a puppet show. There was an introduction to the scrub-suit and paper mask that the doctor will wear. Best of all, there was a free snack (Rob put away two glasses of lemonade and four fist-sized chocolate chip cookies).

The only iffy moment came when Sibyl Gant showed Rob how it feels to have your blood pressure taken. That tight feeling in the bicep scared Rob a little, and as soon as the black band had been unwrapped from his arm, Rob made straight for Pop. Sometimes you need a hug. This was one of those times.

"I don't really think he's nervous, but we're looking for signs, OK?" said David Belli, a 38-year-old economist for the Commerce Department. "He's been a very healthy child," said Cathey Belli, 34. "Right now, I'd say he's mostly excited."

But the big excitement comes Friday. More then.