As the U.S. Department of Education prepares final rules for the $650 million Investing in Innovation Fund, officials face strong concerns from school districts and philanthropies that requiring matching funds from the private sector is unworkable and would turn foundations into the gatekeepers for the federal grants. Concern about the proposed matching-funds requirement for the so-called "i3" grants, which will be given out next year to districts through the economic-stimulus program, was a common thread among the 346 responses the department received during a 30-day public comment period that ended Nov. 9. But that was not the only big concern about how the department is looking to dole out the grants, a small--though highly coveted--piece of some $100 billion in stimulus aid for education. Many school districts objected to the requirement in the proposed rules that applicants show strong evidence of past success in order to justify funding for an innovative strategy, while many education researchers thought the department should be even stricter. Other commenter's did not like that the department placed caps on individual award amounts. Within the comments, there was also a resounding chorus of agreement with the department's efforts to widen the eligibility for the grants, which are currently limited by the economic-stimulus law to those districts that make adequate yearly progress under the No Child Left Behind Act for the previous two consecutive years.