MIDDLE-CLASS and affluent black parents in Shaker Heights, Ohio, wanted to know why their children lagged so far behind their white classmates in what is considered the best school district in the state. Clearly, the achievement gap wasn't the function of poverty or an inferior education, reasons often put forth to explain the gap between black and white students across the country.

The Shaker Heights parents, with funding and support from the school system,called in UC Berkeley anthropologist John Ogbu, a noted figure in the field of minority education, to find the answer.

"The thinking was that because they're middle class, these students will know how to succeed because their parents succeeded," Ogbu says. "But that kind of knowledge is not being passed in the family. The kids had no clue."

The result of Ogbu's study of Shaker Heights is a controversial book called "Black American Students in an Affluent Suburb: A Study of Academic Disengagement." What Ogbu found in Shaker Heights mirrored what he has found in every country he has studied in his 30 years of research.

The under-achieving minorities in these countries, including blacks in the United States, all had one factor in common: They are what Ogbu calls "involuntary minorities."

Involuntary minorities are those who did not immigrate to a country by choice. They became minorities through enslavement, colonization or conquest, a status that continues to shape how they are treated by the dominant group and how they perceive and respond to that treatment. Involuntary minorities developed their identity in opposition to the majority group that had oppressed them. As a result, they are often suspicious of societal institutions run by the dominant group, including the schools, believing that the curriculum threatens and denigrates their heritage.

Voluntary minorities, on the other hand, are those who have chosen to immigrate in hopes of a better future. These minorities see education as a path to success in their new country. They are willing to embrace the new language and new ways, no matter how dissimilar to their own, in order to reap the benefits of an American education.

Ogbu points to the Buraku people of Japan as a comparison. They are ethnically identical to other Japanese. During Japan's feudal ages, the emperor designated the Buraku to be the laborers, the lowest class. They were freed from this designation in 1871, a few years after American blacks were freed from slavery.

To this day, the Buraku lag behind their Japanese counterparts in academic achievement. Yet when they immigrate to other countries, where they are seen simply as Japanese and not Buraku, the the gap gradually disappears. Their school achievement rises.

Similarly, third-generation descendants of Koreans who had been forced into labor in Japan in the last century are among the poorest-performing students in Japan. But Koreans who immigrated to China in search of a better life are the highest-achieving minority group in China.

"The performance of any minority depends on a complex interplay of factors, " Ogbu says.

So what can Shaker Heights and other communities do about the black-white achievement gap? Ogbu recommended a series of school reforms that in Shaker Heights already has increased the number of African American students taking honors and advanced placement classes, narrowed the reading gap between grades 5 and 8, and increased passing rates on state proficiency tests.

But Ogbu put greater emphasis on the reforms he says are necessary in the black community, such as:

-- Creating after-school and weekend educational programs,

-- Raising the visibility of academically successful role models,

-- Establishing awards programs for academic accomplishments,

-- Making clear to children the connection between school success and adult success.

"No matter how you change the schools," he says, "that alone won't solve the problem. That is why I'm emphasizing (community reform). I want this to be part of the discourse."

When Ogbu returned to Shaker Heights to present his findings, many black parents were uncomfortable. Some were angry.

"We didn't disagree on the facts," Ogbu says. "They were concerned about how white people would interpret the findings. They're worried about how they will be used. But there are things that have to be said even if they don't please everybody. Because if you don't say it, we're not going to solve it."