The nonprofit world is applauding President Obama’s Social-Innovation Fund, which he officially announced the creation of yesterday.

But even proponents of the $50-million effort are raising questions about how it should operate.

Matthew Bishop and Michael Green, the authors of Philanthrocapitalism, write on their blog that “implementation is going to be challenging, to say the least. There is not much of a track record of scaling up nonprofits to draw on for guidance. And $50-million is a drop in the ocean compared to the scale of the problems.”

Betsy Fuchs, a philanthropy consultant, agrees. On her new blog, Modern Giving, she also wonders how the fund will pick the “best” charitable programs to support.

“With countless private foundations around the country squabbling to define the ideal due-diligence process, how does Washington know exactly how to build one? How will we be certain that those deemed the ‘best’ programs really are the best programs?” she asks.

On the issue of evaluation, in The Huffington Post, Clayton M. Christensen, a business professor at Harvard University, writes that the administration should create a national discussion among government agencies, grant makers, and others about how to measure social innovation. He also urged the president to look at businesses, and not only nonprofit organizations, when looking for innovative projects.

In all, Mr. Christensen hailed the Obama fund as a “new paradigm for solving social problems.”

Not everyone is convinced of this.

“Clay Christensen piece has left me speechless,” IssueLab, a nonprofit research group, says on its Twitter feed. Neither the argument nor the “paradigm” is new, it says.

What do you think of the social-innovation fund? What questions do you have about how it will operate? How would you run it? Click on the comment button below to share your views.