CHAPEL HILL -- Three diaper changes. Three bikes. Three after-school activities.

Everything has come in sets of threes for the last 18 years for Giles and Beverly Williams, parents of triplets.

Come Saturday, the parents will add one more experience to their list: three diplomas. Their children, Elizabeth, Christopher and Michael, will graduate from East Chapel Hill High School.

"I'm looking forward to less cooking and less laundry, but I'll soon miss the hustle-bustle of a full house," said Beverly Williams.

"Hopefully it will be a little quieter at home, but they're still three left," added Giles Williams. "They'll have to step up and take on some of the chores."

The Williamses are one of two sets of triplets at the high school lining up for diplomas this weekend. East graduates Eamon, Rory and Megan Cullen declined to be interviewed for this article.

While triplets share the same birthday and will be basking in the same glow at the ceremonies at the Smith Center, they're by no means the same person.

Elizabeth is into sports, having played soccer and field hockey. Christopher is the entrepreneur with his own yard-care business, and Michael is introspective, preferring time alone at home.

And although the triplets are moving on at the same time, they're heading to very different places.

Elizabeth will attend Princeton University in New Jersey to play field hockey. Christopher will attend UNC and Michael will head to Western Carolina University in Cullowhee, N.C.

Beverly Williams said that having triplets has always been the norm for her.

"When you don't have one child yet, you don't know what to expect," she said. "So when you have three of them, you just deal with it."

While most parents understand the challenges and unknowns of having a first child, the Williamses had those experiences magnified.

The bottles -- a whole tray had to be made every morning.

The diapers -- at one point the family was using 275 per week.

The lack of sleep -- three crying babies are harder to pacify than one.

Giles Willams said he actually preferred when his children were still babies.

"When they were small and did cry, they didn't cry that loud," he said. "Now when they are just roaming around the house they make a tremendous amount of noise."

Along the way there have been other challenges for the parents of six children. Parent-teacher conference days were almost definitely a whole-day event, and Beverly Williams joked that there are way too many teachers to begin learning all their names.

With so many teachers assigning so much homework to so many children, the nightly rituals for each child were their own responsibility.

Giles Williams said he had the rule that "homework is something they should know how to do, and if they didn't know, they should have asked the teacher after school or during lunch time."

Nearly every aspect of raising the children has been influenced by the fact that there were three hitting the same milestones at the same time.

In high school, the children started becoming involved with their individual after-school activities. This, of course, sometimes made scheduling a nightmare.

Giles Williams said this experience helped teach the kids important time management skills.

"Sometimes right after [field hockey] practice I'd have to pick her up and take her to club soccer practice," he said about Elizabeth. "She would do homework riding down I-40 ... and then she'd be working on homework [on the ride back] when practice was over."

A big family also requires big cars. For several years, the Williamses have parked two Chevy Suburbans in their driveway. And after the triplets turned 16, the parents provided one car for group use (there are four with driving licenses right now).

"You pay a lot of car insurance," joked Beverly Williams.

As any parent knows, having kids is a long-term financial commitment. Three kids heading to college at the same time also can be a very big, long-term commitment.

"There is an advantage of sending three off at the same time when you fill out the financial aid package," acknowledged Giles Williams, referring to the way federal financial aid is calculated. Families with more than one full-time student can get a larger aid award.

But even before college, graduation day will mark a decisive turning point for the Williams family.

"I'm not really sure if you can plan too much for [the transition]," said Beverly Williams. "I think we live and are so busy that you just have to take each day as it comes. I'm sure it will be a big adjustment."

Giles Williams said the transition is one a parent eagerly anticipates.

"I'm ready for them to move on and grow up and take the next step in their life," he said. "I think it is important to get away from your parents."

Until college begins in August, the Williams' house still will be packed and bustling. That means the question remains: In such a big family, who gets to pick the TV shows?

"We don't watch much TV and I get the remote control," Giles Williams said authoritatively.