Responding to a recent rash of criticism, the International Freedom Center yesterday proposed adjustments to its plan for one of the cultural spaces slated for the World Trade Center site, but the changes appeared to do little to address the principal concerns of some of the center’s harshest critics.

The chairman and vice-chairwoman of the Freedom Center, Tom Bernstein and Paula Grant Berry, clarified their vision for the “Freedom Walk” exhibit that has been a particular point of contention, and announced the formation of a permanent 9/11 family advisory group. These ideas were among those laid out in a six-page letter sent yesterday to Stefan Pryor, president of the Lower Manhattan Development Corporation, which is overseeing construction on the site.

Mr. Bernstein and Ms. Berry wrote that a panel of family members of those killed in the attacks is already forming to offer feedback on the center’s programming. The group will operate under the leadership of Ms. Berry, whose husband was killed on September 11, 2001.

The letter asserted that the “Freedom Walk” exhibit, intended to trace the history of freedom in America, would “make the stories of the men and women lost on September 11 an integral part of the historical march toward freedom.” Critics have contended that such a display would portray America in a negative light and would detract attention from the terrorist attacks.

Officials at the International Freedom Center argued that its core exhibit would help visitors to the site to place the terrorist attacks in the larger context of the American struggle for freedom. The letter outlines possible exhibits praising Abraham Lincoln and Martin Luther King Jr., and describing the American press’s role in the Polish solidarity movement. Many people, including President Bush, have argued that the September 11 terrorists targeted not just the World Trade Center and the Pentagon, but freedom itself.

The Freedom Center also offered some of its space as a permanent home for the “family room” currently housed at the LMDC’s offices. The family room would serve as a private area from which relatives of victims of the attack could view the nearby memorial.

In addition, the letter proposed a display that would incorporate artifacts showing the outpouring of international sympathy that followed the attacks.

The recipient of the letter did not have an immediate response to its contents.

“The LMDC is in the process of thoroughly reviewing the IFC’s thoughtful letter,” a spokeswoman for the corporation, Joanna Rose, said.

But many of the center’s critics renewed their objection to the placement on the site of any institution not completely and explicitly related to the September 11, 2001, attacks or to the earlier attempt to bomb the structure in 1993.

“The IFC is attempting to hijack space that is desperately needed to accommodate the almost 10 million visitors who will be making a pilgrimage to sacred ground to pay their respects at the WTC Memorial,” representatives of 14 family groups said in a written statement.

“No distractions will make the stories of loss, generosity, and hope any stronger than the stories directly related to September 11, 2001, and February 26, 1993,” the statement said. “The 9/11 Memorial must stand alone.”

“This space must be solely devoted to the 9/11 memorial and the memorial museum, and anything not related to the events of that day must be moved off the site,” Mary Fletchet, founder of the family group Voices of September 11, told The New York Sun. Ms. Fletchet, whose son was killed in the New York attacks, was also a signatory to the statement.

Some family members viewed the letter as a sign that efforts to put pressure on the Freedom Center are succeeding.

“This shows that the [International Freedom Center] recognizes that they’re up against formidable opposition,” Debra Burlingame, a member of the board of the World Trade Center Memorial Foundation who has been a leading opponent of the center’s plans, told the Sun.