Myra and David Sadker's two daughters play with erector sets and building blocks as well as with dolls and tea sets.

The husband-wife team, both American University professors, have been researching sex bias in the classroom for the last 10 years. Naturally, they wanted to provide a nonsexist home environment for their daughters.

But despite their efforts, they found in some cases they couldn't escape from their own conditioning.

"I found that I would get down on the floor and have the tea party," said Myra Sadker, dean of American University's School of Education and author of a book on sexism in education. "And David would get down on the floor and play with the erector set. . . . It goes to show that you really need to study the specific behaviors or you're kidding yourself."

In the same way, teachers may be relating to students in a sexist manner without even realizing it, the Sadkers said. To help teachers identify ways they may be passing on sex biases in their classrooms, the Sadkers led a three-day training seminar at American University last week.

Forty-five teachers from schools in the District, Prince William County in Virginia and Baltimore County in Maryland assembled for instruction and supervised practice teaching under the auspices of the university's federally funded Mid-Atlantic Center for Sex Equity, directed by David Sadker.

The Sadkers' earlier research convinced them that parents should be concerned about classroom sex bias. Among their findings:

Teachers talk more to boys, give them more counseling, ask them more questions and give them more attention than they give girls.

Teachers discipline boys more often, even when boys and girls misbehave equally.

Teachers are likely to give boys detailed instructions on how to complete a task but show girls how to do something. This may be related to the well-publicized finding that young boys often have greater spatial visualization ability than girls, which may translate to greater mathematical ability.

Teachers usually will talk to boys no matter where they are in the classroom, but often they will talk to girls only when the girls are nearby. "This teaches dependency," said Myra Sadker.

Last week's seminar offered discussions of sex bias in the school curriculum and in teacher interaction, followed by practice teaching sessions with volunteer students. Teachers were graded on these sessions, and were promised confidentiality in return for their participation.

Eighteen District teachers from schools throughout the city were selected to participate in the session. Only teachers of the fourth, sixth and eighth grades were chosen, said a spokeswoman for the center, because gender-based differences in academic achievement begin to appear or intensify in the eighth grade, and the researchers hoped to see whether the sexist socialization appears, and can be corrected, in earlier grades.

Teachers in the sessions were selected from the three school systems, said Myra Sadker, to help researchers understand whether race changes the interaction between teachers and their students. All of their present findings come from research on white middle-class school children, she said. Last week's training session will be followed by a year-long research and training project at a District high school, whose name Sadker would not release because negotiations with the school have not been completed. The $40,000 study will be funded with a grant provided by Title IV of the Civil Rights Act.

The center does research and provides practical teaching tools for overcoming sex bias. It serves six states, including Maryland, Virginia and the District, on an annual budget of about $350,000, "which amounts to about a penny per student, since we serve about four million students," said David Sadker.

The center also helps schools comply with Title IX regulations (of the 1964 Civil Rights Act) requiring that schools provide equivalent educational opportunities for boys and girls.

Myra Sadker also counsels parents in the area of sex bias. She recommends that parents visit the school library to see whether books present girls and boys in stereotypical roles, and to visit the classroom to see whether their children receive enough attention.

"We find that achievement is closely related to participation in classroom discussion," said Sadker, "so it's important to see whether your child is quiet and involved."

Parents should try to help teachers overcome unconscious biases, she said. "They don't mean to do it," she said. "Most teachers are fair and good sorts who want to do the right thing. It just happens that they teach boys and girls differently."