IN NEW YORK and Chicago, two large cities with supposedly unsalvageable public school systems, the just-concluded school year has seen a dramatic reach for improvement. The two cities are proceeding by markedly different paths. In Chicago, last fall saw the start of a radical decentralization, which gave day-to-day power over individual schools to parents and teachers through almost 600 "local school councils." Those councils have proceeded to hire principals, draw up performance contracts, draft school improvement plans and start budgeting for them in an impressive show of enthusiasm and involvement.

In New York the crusading new schools chancellor, Joseph Fernandez, is trying to undo the pernicious effects of a very different decentralization plan that was launched 20 years ago and that succeeded only in farming out power to 32 entrenched bureaucracies. Mr. Fernandez spent the year struggling to get the power of accountability back into the chancellor's office. In March he retrieved the right to transfer (though not fire) incompetent principals, who till then had enjoyed an unparallelled protection known as "tenure to building." His attempts to go a step further -- to block hirings he disagreed with and to veto candidates being considered by district boards -- have run into much stiffer opposition. Mr. Fernandez also needs to retrieve power from the custodians' union, whose contract requires only three floor-moppings a year, and from the soon-to-be-defunct Board of Examiners, which tests city teachers.

Such ignominious fallout from New York's decentralization has made observers rightly cautious of Chicago's. Designers of the Chicago plan, mindful of these traps, drew up a blueprint that is only superficially similar. Instead of district school boards -- each, in New York, the size of a normal city system -- Chicago's schools are now run individually, and school system employees can't run for the parent or teacher seats. So far, unpaid parents and teachers have put in countless hours and have come up with a flood of small-scale proposals now slowly being implemented. The lesson is not necessarily that this method will work but that the ideological cast of reform is less crucial than the extent to which it actually draws parents and teachers into active collaboration in running schools.