WASHINGTON - There is almost no scientific evidence to back up the U.S. intelligence community's use of controversial interrogation techniques in the fight against terrorism, and experts believe some painful and coercive approaches could hinder the ability to get good information, according to a new report from an intelligence advisory group.

The Intelligence Science Board examined several aspects of interrogation, and its 374-page report said more than four decades had passed since any significant scientific research had been conducted on the effectiveness of many techniques the U.S. military and intelligence groups use regularly. Intelligence experts wrote that a lack of research could explain why abuses had been alleged at U.S. facilities in Afghanistan, Cuba and Iraq.

"Since there had been little or no development of sustained capacity for interrogation practice, training or research within intelligence or military communities in the post-Soviet period, many interrogators were forced to 'make it up' on the fly," wrote Robert Fein, chairman of the study, published by the National Defense Intelligence College.

He added: "This shortfall in advanced, research-based interrogation methods at a time of intense pressure from operational commanders to produce actionable intelligence from high-value targets may have contributed significantly to the unfortunate cases of abuse that have recently come to light."

The study, sponsored by the Defense Intelligence Agency and the Pentagon's Counterintelligence Field Activity, was posted last week on the Federation of American Scientists' Web site.

In it, experts said popular culture and ad-hoc experimentation had fueled the use of aggressive and sometimes physical interrogation techniques on those captured on the battlefields, even if there was no evidence to support their effectiveness. The board, which advises the U.S. director of national intelligence, recommended studying the matter.

"There is little systematic knowledge available to tell us 'what works' in interrogation," wrote Robert Coulam, a research professor at the Simmons School for Health Studies in Boston. He also wrote that interrogation practices that offend ethical concerns and "skirt the rule of law" might be narrowly useful, if at all, because such practices could undermine the legitimacy of government action and support for the fight against terrorism.

The Bush administration has long advocated the freedom to use aggressive interrogation tactics on terrorism suspects. After abuses surfaced at Iraq's Abu Ghraib prison and the Navy's prison at Guantanamo Bay, Cuba, Congress forced the government to conform its approaches to long-standing military doctrine but allowed a loophole that lets the CIA continue other techniques.

The Army's new field manual on intelligence, approved in September, bans some of the most aggressive techniques - such as waterboarding, beatings, and sensory or food deprivation - and draws clear boundaries for all military personnel who participate in interrogations.

Army officials abandoned more coercive techniques because of the scandals and evidence that Army and contract interrogators had developed approaches in the field based on vague guidance. The new study said there might be no value to coercive techniques at all.

"The scientific community has never established that coercive interrogation methods are an effective means of obtaining reliable intelligence information," wrote Col. Steven Kleinman, who has served as the Pentagon's senior intelligence officer for special survival training.

He also wrote that intelligence gathered with coercion was sometimes inaccurate or false, noting that isolation, a tactic U.S. officials have used regularly, causes "profound emotional, psychological and physical discomfort" and can "significantly and negatively impact the ability of the source to recall information accurately."

Read the Intelligence Science Board's report via http://go.philly.com/interrogateEndText