Taking of the census is vital to America's picture of itself. So much depends on this head count every 10 years, including voting, poltical power, money, and federal social programs. It needs to be done as accurately as possible.

Unfortunately, when census-takers go door-to-door each 10 years, their methods have frequently left many uncounted.The homeless, illegal Hispanic immigrants, and many black men have been missed in previous census efforts because the usual survey methods do not take into account their unique circumstances or fears.

The Census Bureau hopes to to correct that in 1990, based on research by those who study these shadow populations. Part of the census taker's challenge is to count people without scaring them off.

For example, many black men fear that giving census information will cause their families to lose welfare checks. Generally, families are not eligible if there is an employable adult in the home.

Illegal Hispanic immigrants fear deportation and the homeless have never been effectively counted because they lack permanent addresses. In addition, young black men sometimes have unique lifestyle patterns sleeping at one home, eating at another, keeping clothes at a third.

In that case, census workers have experimented with adding additional questions such as "Does anyone else keep clothes here?" to their normal list to get a better count.

The census conference should focus on such innovative approaches and broaden confidentiality programs. An accurate count of all of these populations is vital, both in simply knowing population increases and in developing programs to help these groups.