Imagine, if necessary, that you're white. You turn on the television after a long day of work, only to find that someone has tampered with all of your favorite shows. Instead of comedies set in white suburban households and dramas revolving around the passions and actions of white characters, every show features an all-Asian American cast.

The shows are set in Los Angeles and New York, high schools and shopping malls -- all familiar places where you would expect to find white Americans, but somehow they have disappeared without a trace. You flip through dozens of broadcast, extended basic and premium cable channels in mounting desperation, searching in vain for a recognizable white face.

You manage to catch a glimpse of the closing scenes of a "Beavis and Butthead" rerun on MTV. You also see Ronald McDonald doing a commercial, but you look closely at his eyes and figure out that there's an Asian American actor underneath all that white makeup.

Eventually, you resign yourself to watching an Asian American version of "Friends." It's entertaining enough, but you can't quite overcome the sense that something is horribly wrong out there in TV land. Sure, TV shows aren't known for their accurate depictions of the real world, but this is ridiculous.

In a fair marketplace of ideas, this scenario would occur in every American household, night and day, for two weeks out of every year, representing Asian Americans' four percent share of the U.S. population. After all, we Asian Americans already know how to enjoy television, even if we rarely have the opportunity to see ourselves depicted in roles bearing any resemblance to our own experiences. Shouldn't all Americans develop this skill?

If white Americans learned how to relate to, and root for, Asian American protagonists, maybe Hollywood would cast us in leading roles once in a while, instead of distorting us beyond all recognition. None of the Asian Americans I have ever known has lived in a Shaolin temple, spoken in the language of fortune-cookie aphorisms, spent a day at home kneeling in a kimono, fought in a kickboxing death match, summoned powers of reincarnation over a cup of chai latte, sought world domination, eaten a poodle, committed hara-kiri, or awaited rescue by a white hero. Apparently, however, a great many Americans like to imagine a world where Asian Americans either are confined to these stereotypes or don't even exist.

It's unlikely that Hollywood screenwriters and casting directors are trying to pass off these images as authentic depictions of Asian Americans. From living amidst 1.3 million Asian Americans in Los Angeles County, they ought to know us pretty well. And, while Hollywood studios have had a poor track record in providing opportunities for Asian American creative expression, it's doubtful that they harbor a racist agenda to promulgate stereotypes. Indeed, if conservative commentators are to be believed, Hollywood culture is beset with an excess of politically-correct solicitude for the sensitivities of people of color.

It's more plausible to conclude that media stereotypes of Asian Americans are simply the product of the free market at work: Hollywood as dream factory. We don't see Asian Americans in recognizable movie roles because most of the ticket-buying audience prefers to fantasize about an America where white experiences are central, white authority is unchallenged, and racial hierarchy is preordained.

As for television, the very idea of an America in which Asian Americans exist, live relevant lives, and dream dreams is of so little interest to the general public that it is a remarkable occurrence whenever a recognizable depiction of an Asian American appears. In her recent book "Asian American Dreams," award-winning journalist Helen Zia writes of her family's lifelong habit of watching for these appearances:

It was so rare to see a real Asian American on television when I was a kid that we had a family ritual when one was spotted. It constituted what I now call an "Asian sighting." A hoot went out: "Hey, come see this, look now!"

Real Asians didn't include Hop Sing, the Cartwright family's houseboy on the TV show "Bonanza," or David Carradine, Jerry Lewis, or the numerous white actors who donned yellowface to play Asians. We only shouted when we saw regular Asian Americans like us, on the news, game shows, variety programs, or beauty pageants. It was a rare event.

We would then drop everything and make a frenzied rush to the tube to see who had entered that mysterious TV land where people of Asian descent were virtually nonexistent. My parents participated enthusiastically in the routine as well. They liked to assess for us kids the looks, ethnicity, demeanor, intelligence, and other vital signs of the real Asian, which they conducted in a manner as succinctly and passionately as a sports announcer. . . .

Asian sightings are more common now, but they are still infrequent enough to create a thrill whenever real Asians appear on the screen, as martial artists, for example, or television reporters. We cheer to see a Chinese man, chubby and middle-aged, as the star of a television series, or an Asian American female character who is aggressively nasty, so un-Suzie Wong. We heave a sigh of relief when a movie like "Mulan" is released, using real Asian American actors' voices, and it is not "ching-chong," as one friend puts it. Each Asian sighting that breaks through the constricting stereotypes gives another reason to celebrate.