In a move partly designed to demonstrate its commitment to transparency, the Bill & Melinda Gates Foundation, the world's largest private philanthropy, is calling attention to its efforts to address the perception among grantees that it is secretive and often difficult to work with, the Associated Press reports.

In its most recent annual report, posted online earlier this week, foundation president and CEO Jeff Raikes drew attention to the results of a grantee perception survey released in June that gave the foundation poor marks for communicating its goals and strategies and for explaining its grantmaking process. Raikes also outlined some of the things the foundation is doing to address those concerns.

The exercise in transparency has not silenced the foundation's critics, however. They include Pablo Eisenberg, senior fellow at the Center for Public and Nonprofit Leadership at Georgetown University, who has criticized the foundation for having a small, unrepresentative board of directors — the Gateses and Warren Buffett. While the foundation has several advisory boards and employs other consultants, they are a poor substitute for a governing board that includes strong voices from outside the foundation, said Eisenberg. "There's no substitute for other points of view and perspectives around the table when a so-called board is about to make a decision on priorities and programs affecting $3 billion a year or more."

The foundation will continue to focus on global health in 2011, particularly vaccine research and distribution, and its ongoing push to eradicate polio, said Raikes in his president's letter. "The next five years offer a historic opportunity to have an impact on the health and welfare of people in the developing world," he added. "Even in the face of very tough economic times across the globe, I am optimistic when I think about all that we can accomplish together with our partners."