Robert Hooks, the actor and ex-Washingtonian, greeted his 7-year-old son with a kiss the other day and heard the youngster spouting gobbledygook in reply. When Hooks asked young Chris what he was talking about, the child responded: "I'm not Chris, I'm Mork."

"He was talking this strange way," recalls Hooks, "because he had seen a man standing on his head talking that way to an egg" on the new TV series "Mork and Mindy." "My God, what's happening?" Hooks says he asked himself. "I didn't know he watched this stuff."

Hooks, Cicely Tyson, FCC Commissioner Abbott Washburn and others yesterday were telling such stories at a conference designed to encourage parents to talk about television with their children.

The session focused on Parent participation TV Workshops (PPTVW) a nationwide program in which instructional materials on specific NBC specials are sent to school and community groups in order to facilitate discussion of the programs among students, parents and teachers.

The PPTVWs are financed by NBC and conducted by Teachers Guides to Television, a biannual magazine partially supported by the National Association of broadcasters. The magazine and WRC-TV cosponsored the conference at L'Enfant Plaza Hotel yesterday.

Tyson told the crowd about her own parents, who separated when she was 11. She was "very, very close" to her father, she said, and they shared "wonderful moments of exchange." But when her father left, her mother worked so hard she didn't have much time to talk. "I long for those moments when she would sit by the window and talk about her life," said Tyson. "There are so many questions I wish I could have asked." She urged parents to make sure their children "understand you are their friend, that their loneliness can be alleviated."

Although everyone at the conference appeared to agree that families should watch television together, Tyson said she likes to watch her own work alone so she can be objective about it.

A tape of a Baltimore Parent participation TV Workshop was shown at the conference. The students had watched part of "A Woman Called Moses," an NBC special with Tyson and Hooks, and were discussing it with a group of adults. Some of the students were clearly video-savvy. Referring to a scene in which Tyson's character is caught in a fire, one student remarked "as soon as you say the word 'television,' you know she's going to be saved," another observed that escape was inevitable because the show is "a four-part story."

Commissioner Washburn reported that every Sunday his family discusses what to watch during the coming week. He listed some of his own favorites, including "Welcome Back, Kotter" ("an innovative teacher brings out the best in these Sweathog kids . . . we cheer when one of the Sweathogs make it to the student council").

"Our daughter and her friends strongly emphathized with 'James at 15,'" said Washburn. They wouldn't miss it NBC canceled "James at 15" this year, so Washburn issued a call to NBC's president: "Mr. Silverman, if you're out there, maybe you can work some of your special magic and give us another 'James'."