For the past six years, minority groups have monitored their portrayal on U.S. television, and demanded that the networks show the full diversity of American life. Media watchdog groups say the networks are making progress, but see room for improvement both on-screen and behind the camera.

Alex Nogales, president of the National Hispanic Media Coalition, says the issue is partly about jobs, both for actors in front of the camera and for writers, directors and producers behind it. He says Latinos like him are more visible on television that they were six years ago, but are still underrepresented, especially in behind-the-scenes executive positions.

Who else is going to tell our stories? Who else is going to say this is how we are, this is who we are, this is what we are worth? Who else is going to do it, if not us? Other people will try, and they'll get it half right," he said.

And they will get it half wrong, he added.

For minority groups, Mr. Nogales says television provides visibility. He says successful Latinos today may be judges, doctors, or other professionals, but he said that is seldom seen.

If you are absent from television, you are absent from the view of the America public," he said. "And how we are perceived is how we will be treated. So if you don't see us, and the only time that you see us is in a one-dimensional fashion, and it is a negative stereotype, you're going to be treated that way.

The advocacy groups cite ABC - the American Broadcasting Company - as a leader in promoting diversity on the air. They say several of the network's shows, including Commander-in-Chief, which concerns a woman U.S. president, have Asian-American writers, producers and directors.

Karen Narasaki of the Asian Pacific American Media Coalition says that infusion of talent is helping the network.

ABC is also the only network with two Hispanic-themed programs, The George Lopez Show and Freddie. But the groups say all of the networks have a long way to go in portraying a diverse Amarica.

The ethnic groups rated four major networks in an annual Diversity Report Card, and they say that on network television, American Indians are most poorly represented of all groups.

Mark Reed is a Native American actor who traces his ancestry to the Mohawk and Apache tribes. He says when producers depict his people, they often try to do it in a positive way, but end up offering unrealistic portrayals.

"Fictional representations is what we get now of our cultural past," he said. "They have little regard to true accuracy of our culture. They'll put together something based on their image, their idea, their concept. It's not necessarily the image of the tribes that exist in the United States."

He says there are at least 600 tribes, each with its distinctive characteristics.

Alex Nogales says Latinos alone make up 14 percent of the U.S. population and have purchasing power of $700 billion a year. He says their underrepresentation in network television is shortsighted, and that the networks would be wise to target this market segment in their programs and their advertising.