Tiffany Lewis, the youngest of 11 children in a Southeast Washington family, usually spends her Saturdays watching television and going shopping with her mother.

But on Saturday, Lewis, a 15-year-old freshman at Woodson Junior High School, gave up her free time in order to attend a workshop at Howard University designed to help black teen-agers boost their self-esteem and avoid unwanted pregancies.

"I really didn't know that much about pregnancy or anything," said Lewis.

"I feel like I learned what I'm capable of doing and not doing in my life. Before, I was kind of doubting it."

The workshop was the third in a series sponsored by the D.C. chapter of Delta Sigma Theta, a sorority composed of black professional women.

In Washington -- a city with the nation's highest rate of teen-age pregnancy and one of the most serious heroin problems -- the workshops serve a special need, according to Margaret Washnitzer, the sorority chapter's president.

"We looked at all the problems these kids face, and the underlying one is that they had no sense of self-esteem," said Washnitzer. "Our whole thrust is to make girls and boys aware of who they are.

Most of the 100 teen-agers who participated in the workshops were referred by counselors or teachers at their schools.

Some had been pregnant, or had drug problems or were truant, Washnitzer said.

They listened to lectures about black culture and attended discussions about motivation. The most popular session by far, Washnitzer said, was "My Physical Self," which featured frank discussions about sex and contraception, led by a psychiatrist and a gynecologist.

"The adults have been shocked that these kids are so sexually advanced, and a lot of adults think we should take the abstinence view, but the reality is a lot of these kids are very active," she said. "Of course, we discuss the values of postponement and knowing who you are. I thought it was really interesting that four fathers brought their sons to that one."

At the end of the workshops, the 100 students filed into an auditorium to listen to D.C. Councilwoman Charlene Drew Jarvis (D-Ward 4) and receive certificates.

"You need to be your own best public relations person," Jarvis said. "You're foolish if you think you're hopeless, because you control your destiny with your minds."

The message was not lost on Tiffany Lewis, who said she would like to be a lawyer or a television news anchorwoman. The program made her think she might be able to fulfill her dream of attending college in California.

Lewis said she is especially proud of the certificate she received for attending the workshops. "I'm going to take this home and show it to my mother. Maybe she'll even frame it."