BOISE, Idaho — After studies emerged more than a decade ago showing that the highest rates of physical and sexual assault happen to women ages 16 to 24, programs to prevent abusive relationships have concentrated on high school and college students.

Some initiatives have shown promise, but overall statistics remain largely unchanged: the most recent government report stated that nearly one in 10 high school students said they had been physically hurt by a boyfriend or girlfriend.

Now a diverse group that includes the Centers for Disease Control and Prevention, the Robert Wood Johnson Foundation and federal lawmakers is trying to forestall dating violence by addressing even younger students: middle schoolers. The goal is to educate them about relationships before they start dating in earnest, even though research shows that some seventh graders have already experienced physical and emotional harm while dating.