WASHINGTON — THE first blush of response among educators this spring for the Bush administration's new high-profile focus on education was enthusiasm for the long-sought attention.But the jockeying is beginning in earnest now over the particulars of the administration's plans to overhaul American schools. The most sweeping single practical step in the Bush program is the move toward national student testing that would compare states, and perhaps districts and schools, to each other and themselves over time. But national testing is provoking some widespread concern among educators and some politicians over whether the assessments will strengthen weak schools and students or just weaken them further. One key question is the quality and character of the tests: Will they be useful measures of higher-order thinking or cheap and efficient multiple-choice tests? The kind of testing is crucial because on both sides of the issue people agree that the test shapes the curriculum. "We know that any kind of testing and assessment has a powerful effect on what's taught and how," says Michael Cohen, executive director of the National Center for Education and Economy. The national tests proposed by the Bush administration are intended as a kind of enforcement for new "world class" standards on what students ought to know and be able to do in English, mathematics, science, history, and geography. The tests, according to the Bush team's plan, should motivate students and schools to meet the standards. They would measure student mastery of key subjects at Grades 4, 8, and 12. The skeptics are concerned that the test will be used to sort out winners and losers among students and schools without producing useful new information. "The question is what good does it do you to make a comparison? Tests don't tell what to do about it," says Monty Neill, associate director of the National Center for Fair and Open Testing, an organization that is particularly concerned with bias in testing. The most widespread worry about testing comes down to fear that the federal government, for thrift and efficiency, will only use multiple-choice tests. These tests proliferated during the 1980s as the nation grew conscious of how badly educated its young were compared to other industrialized countries. Test results by school and district carry powerful political charges for school boards and administrators. Complaints arose through the decade of teachers "teaching the test" and as a result, students lack ed the more complex skills of writing and analytical thinking. One way around that problem is creating tests that are worth teaching. The National Center on Education and Economy has developed an examination system with the Learning Research and Development Center at the University of Pittsburgh. It assesses projects that a student has worked on for weeks or months or portfolios of a student's work, and would allow students a flexible amount of time to complete examinations. This is one of the major proposals being considered by the National Council on Testing and S tandards, a group conceived by the administration and created by Congress. It will be making critical decisions on testing at the end of the year. Educators suspect that national testing is being intended as a tool to help parents evaluate schools under a voucher-style system of school choice. The Bush plan is to make the national test voluntary, although educators say participating would be politically inevitable.