SAVANNAH PENCE, 15, says she wants to be in touch with her parents  but also wants to keep them at arm’s length. She says her father, John, made sure that she and her 19-year-old brother, Alex, waited until high school before they got cellphones, unlike friends who had them by fifth grade. And while Savannah described her relationship with her parents as close, she still prefers her space.

“I don’t text that much in front of my parents because they read them,” she said. And when her parents ask who is on the phone? “I just say, ‘People.’ They don’t ask anymore.”

At first, John Pence, who owns a restaurant in Portland, Ore., was unsure about how to relate to his daughter. “I didn’t know how to communicate with her,” Mr. Pence said. “I had to learn.” So he took a crash course in text messaging  from Savannah. But so far he knows how to quickly type only a few words or phrases: Where are you? Why haven’t you called me? When are you coming home?

When his daughter asks a question, he typically has one response. “ ‘OK’ is the answer to everything,” he said. “And I haven’t used a question mark yet.” He said he had to learn how to text because his daughter did not return his calls. “I don’t leave a message,” he said, “because she knows it’s me.”

Savannah said she sends a text message to her father at least two or three times a day. “I can’t ask him questions because he is too slow,” she said. “He uses simple words.” On the other hand, her mother, Caprial, is more proficient at texting and will ask how her day was at school or how her friends are doing. (Her mom owed her more facile texting skills to being an agile typist with small hands.)

Early on, Savannah’s parents agreed that they had to set rules. First, they banned cellphone use at the dinner table and, later, when the family watched television together, because Mr. Pence worried about the distraction. “They become unaware of your presence,” he said.

Mr. Pence is well aware of how destabilizing cellphones, iPods and hand-held video game players can be to family relations. “I see kids text under the table at the restaurant,” he said. “They don’t teach them etiquette anymore.” Some children, he said, watch videos in restaurants.