Americans' first instinct in the aftermath of the September 11 attacks was to give. The result was an unprecedented national outpouring of close to one billion dollars in charitable contributions. U.S. charities are discovering that collecting the money was easier than figuring out how to dispense it.

The first issue is coordination. Hundreds of different charities across the United States have collected money. They must now work together to distribute it equitably.

The money was donated to the victims of the attack. And that, says George Ruotolo of the American Association of Fundraising Counsel, a group that sets national standards for charitable organizations, raises another issue: How do you define a victim?

"The human toll of September 11 is by itself substantial," he said. "The fallout of the human toll the families of the workers and the law enforcement people that were lost their families' needs exist. So just the size of this is pretty awesome."

The list of victims grows, Mr. Ruotolo says, if you add the workers who lost their livelihoods because their businesses were destroyed in the attacks.

"The other complexity is that the U.S. government is going to be contributing money to the families and these charities are going to be contributing money to the families, so I think the convergence of philanthropy and Federal and state support has to be done in a way that those two things are coordinated," he said

Bennett Weiner of the Better Business Bureau's Wise Giving Alliance, a group that watches over non-profit finances, worries about the impact the donations will have on charitable giving in general.

After having donated so much money to the victims, he wonders, will Americans have money left to give to conventional charities?

"The last quarter of the year for most charities is the most important," Mr. Weiner said. "Charities really depend on this time of the year to make their ends meet. There is concern that it is going to affect the financing of a number of groups."

That could be devastating, Mr. Weiner says, because charities in the United States support everything from medical research and aid for the poor to education and environmental protections. "The hope is the renewed spirit of generosity might spill over into helping other causes," he said.

Mr. Weiner says Americans already give more to charity than people in any other country. He says that spirit of giving will be tested in the months ahead.