SECRETARY OF EDUCATION Lamar Alexander touts it as an important step toward reinvigorating America's schools. Gov. William F. Weld '66 has made it a major part of his education reform strategy. Conservatives love it, and many liberals are toying with the idea. The program is school choice, and it's the hottest, most dangerous innovation in public education today.

School choice experiments generally fall into three categories: those that enable parents to transfer children to other schools within their district; those in which parents can place their children in other districts and those that offer parents public money to pay partial tuition costs at a private school.

Although choice within the public system may be beneficial, there must be certain provisions which ensure that ethnic and economic background does not prevent some students from participating. Pure choice without government intervention will not only hurt the schools and children who need the most assistance, but it will also deepen racial and economic segregation in schools.

CHOICE WITHIN public school systems is not necessarily harmful. In choosing a school, parents become active participants in their children's education. If choice programs prompt schools to make serious improvements, students will be better off.

But there are several more ifs. Choice is okay if transportation is provided for school transfer. It's also acceptable if government monitors the level of minorities in schools, and if it fully informs parents of their options in a choice program. But even if these conditions are met, choice must not be regarded as a panacea for American education.

There are countless educational issues which need to be addressed. Schools need more money to make building repairs, buy books and attract high-quality, energetic teachers. They should adopt fairer and more comprehensive methods of evaluating students than the current system of standardized testing. Students are suffering from increased class size, and educators are realizing that traditional teaching methods are just not adequate anymore. Choice alone addresses none of these issues.

According to Harvard Professor of Education Richard F. Elmore, there is no clear evidence that school quality will improve as a result of choice plans. What some programs will do is widen the gap between the haves and have-nots in education.

More resourceful parents will do research and make more informed choices about schools. And it will be tough luck for the students whose parents are less aggressive. Parents with money will provide the transportation necessary for their children to get to the best schools; poorer parents will have more limited choices.

Massachusetts's school choice program, which does not fund transportation to schools in other districts, has a total of 781 students who have left their districts. According to statistics released last week by the state Department of Education, only 7 percent of these students are nonwhite or Hispanic, while 18 percent of all Massachusetts public school students are minorities. These figures suggest that not all students have an equal opportunity to take advantage of the program.

Unregulated choice programs present a barrier to the goal of an integrated society. Certainly American schools and neighborhoods are already largely segregated. Poorly planned choice systems will reverse the progress toward integration made in the last 30 years: White parents will avoid schools with significant minority populations. Popular schools will select students they perceive as less likely to cause problems, which may mean choosing whites over minorities. The effect will be a systematic resegregation of many districts.

"Controlled choice" plans, such as the one currently used within Cambridge, are ideal. In Cambridge's system, transportation for school transfer is funded, and the racial balance of each school is taken into account when deciding which students can switch schools. Unfortunately, other communities will be less willing to provide the resources necessary to guarantee transportation and establish the Parent Information Centers which help Cambridge parents make educated decisions.

The worst choice plan is a voucher system in which public money is used to pay partial tuition costs to private schools. Proponents dream that the magic of the free market will increase competition and bring about the best possible results for schools. But the results are more likely to resemble our private health care system, in which people who use vouchers in the form of Medicare or Medicaid get vastly inferior care. Moreover, the Andovers, Exeters and Deerfields will still pick the kids they want, making a great influx of inner-city kids unlikely.

ALREADY, about 30 states have passed laws authorizing a variety of choice programs. This experimentation should be followed closely, but the federal government should not be encouraging choice plans which cause the privatization of public education or increased segregation.

Choice can assist in bringing parents into the education system and pushing schools toward higher standards. But there must be government safeguards so that public education does not become even less effective in guaranteeing equality of opportunity for all Americans.

Poorly planned school-choice programs will widen the gap between the have and the have-nots.