Democrats have made political hay in recent years with accusations that the GOP-controlled Congress prefers partisan witch hunts to sober-minded oversight of federal agencies and programs. Now, it appears, House Republican leaders have their own concerns about oversight.

House Speaker J. Dennis Hastert (R-Ill.) has ordered a top-to-bottom assessment of congressional oversight and earlier this year he urged lawmakers and staff to participate in a Heritage Foundation training program to raise the quality and effectiveness of their work.

Hastert and other GOP leaders have also pressured committee chairmen with oversight responsibilities to show that Republicans are getting tangible results, which triggered a recent spate of House Budget Committee hearings into waste, fraud and abuse. On his Web site, Majority Leader Richard K. Armey (R-Tex.) has taken to touting a GOP "Waste-O-Meter" that tallies the amount of wasteful spending purportedly uncovered by oversight committees.

"The speaker has been saying he wants more effective programmatic oversight to make government work and get away from some of this more sensational oversight," John Feehery, Hastert's press secretary, said yesterday.

The new efforts by House leaders represent a shift from a more partisan approach to oversight favored soon after the Republicans gained power in 1994. Then-Speaker Newt Gingrich made plain his desire to expose alleged corruption in the Clinton administration, and a number of committees--most notably one headed by Rep. Dan Burton (R-Ind.)--became subsequently embroiled in controversial investigations of the administration.

At the same time, the Republicans downgraded traditional oversight as part of their effort to trim back the size of the congressional bureaucracy. For instance, the Commerce Committee--a crusading, if controversial, force under former chairman John D. Dingell (D-Mich.)--lost more than half the investigators and lawyers once involved in conducting investigations.

The result, according to analysts and lawmakers of both parties, is that with some notable exceptions--including probes of the Internal Revenue Service and Persian Gulf War-related illnesses--key GOP committees have fallen short in uncovering new problems, illuminating how government works or turning up information beyond what's been in press accounts.

"Most oversight focuses on 'scandal' or consists of quick expositions of isolated problems with no follow-up," said Virginia L. Thomas, a former aide to the House GOP leadership and now a government scholar with the conservative Heritage Foundation.

Eric Thorson, a government compliance consultant and former congressional aide who organized the Senate Finance Committee's blockbuster probe into charges of IRS abuses of taxpayers, added: "There's been a marked decrease in the really hard-hitting oversight that has been done in the past."

Some Republicans say such criticism ignores their real accomplishments. The Commerce Committee, for example, showed the government how it could save millions of dollars in Medicare and Medicaid costs and blew the whistle on lavish overseas travel by former Department of Energy chief Hazel O'Leary, according to lawmakers and aides.

"Pound for pound, Republicans have been far more effective--and far more responsible" than the Democrats in conducting oversight, said Steve Schmidt, a spokesman for the committee.

Next to legislating, oversight is perhaps Congress's most important job, with close to $1.8 trillion in annual federal spending to be scrutinized. But with hundreds of hearings every year on a mind-numbing array of subjects, assessing the quality and impact of congressional oversight can be a highly subjective exercise.

Complicating such assessments are differing perspectives on the proper role of oversight: Fiercely skeptical of regulation and committed to downsizing government, Republicans have been less interested, for example, in taking a close look at the pharmaceutical industry or Wall Street firms that were once a favorite target of Democrats.

Meanwhile, Rep. Henry A. Waxman (Calif.) and other Democrats charge that Republicans have become so obsessed with embarrassing the Clinton administration that their investigations lack credibility. The GOP says Democrats have done little more than obstruct probes of serious wrongdoing by the administration.

The Commerce Committee, with broad purview over telecommunications, health, nuclear energy, consumer protection and power marketing, highlights some of these different perspectives.

Dingell chaired the Energy and Commerce Committee, as it was formerly called, as well as the oversight and investigation subcommittee for 14 years, and poured unprecedented resources and manpower into probing agencies and regulated industries. At its apex, the oversight subcommittee had a stable of 20 full-time investigators and lawyers, including several detailed from the General Accounting Office.

Dingell's committee highlighted the Pentagon's $640 toilet seat and $7,000 coffee pot, uncovered corruption in the generic drug industry, helped topple a top Reagan White House adviser, and exposed insider trading on Wall Street and deception by tobacco industry executives.

But the Democrats' oversight was far from perfect. Many lawmakers complained of Dingell's bullying tactics in going after Reagan and Bush administration officials, and his hearings into alleged fraud by academics and scientists unfairly damaged some reputations.

After the Republican takeover in 1994, Congress's new leadership slashed all committee budgets and staffs by a third as part of a cost-cutting move. Rep. Thomas J. Bliley Jr. (R-Va.), the new chairman, stripped all his subcommittee chairmen of direct control over staffers--a move designed to consolidate his control over the direction of the committee--and reduced the number of investigators and lawyers.

The results of this transformation are the subject of intense debate. The committee has highlighted the epidemic in the use of so-called "date rape" drugs and promoted a safer blood supply, among other issues. And just this spring, in response to the new oversight campaign by House leaders, Bliley issued a blizzard of letters, demanding that the Environmental Protection Agency toughen its standards for diesel truck pollution; blasting the Food and Drug Administration for allowing the importation of "counterfeit" prescription drugs, and urging the Department of Health and Human Services to crack down on the overbilling of Medicare for prescription drugs.

Bliley hit pay dirt this summer when HHS Secretary Donna E. Shalala promised a major overhaul of the government's Medicare drug reimbursement procedures that would require private insurance companies that process Medicare claims to switch to more accurate pricing information for dozens of drugs.

Despite such efforts, critics say the committee has rarely conducted ground-breaking research and left whole areas of responsibility--including the impact of the historic boom in the stock market and the long-term effect of the FDA's fast-track approval of drugs--largely uncovered. The committee also botched a high-profile hearing this spring into allegations of illegal marketing of fetal tissue.

Republicans on the committee thought they had the goods for sensational congressional theater. A medical technician, Lawrence D. Alberty Jr., claimed to have seen clinic doctors killing live fetuses and illegally marketing the parts for exorbitant fees. Some Republicans thought they could use Alberty's testimony to build momentum toward legislation curtailing medical research with aborted fetuses.

But the March 9 hearing quickly unraveled when Democrats revealed startling information about the star witness: He had admitted in court documents to having lied about the whole problem.

Angry Republicans accused the Democrats of sandbagging them by holding back the information until the morning of the hearing. "The mistake the committee made was believing the minority would act with some degree of ethics in the matter," Schmidt said.

Still, some committee Republicans say they can only do so much. "It's just an enormous task we have before us and there's no way that you can look at all the different things within our jurisdiction," said Rep. Fred Upton (R-Mich.), the chairman of the subcommittee on oversight and investigations. "We have more than a full plate, but overall . . . we're still spending less than the Democrats spent when they were in charge."