"The schools and programs that the folks put in place, only now are they ramping up and students are starting to go through them. So you won't know what the outcomes are until like 5, 7, 10 years from now," he said. "That said, I think there are some things that are going generally better than we'd expected and some things that we've definitely taken as lessons."
One of the positive outcomes Zuckerberg points to: Newark's teacher contracts, which, among other things, provide for performance-based pay bonuses for the district's best teachers. He says the contracts are "better than anything that had been negotiated before...to reward teachers who were the top performing teachers and hold teachers accountable who were not performing well."
Zuckerberg admits that he and local leaders could have done a better job engaging the community and soliciting ideas about how to spend the money.
"I think one of the things that we took away from this is that we wanted to do our next set of work in a place where we can engage more directly with the community and a place that we care about a lot. The Bay Area just fit that well," Zuckerberg said.
The couple's broader philanthropic goals center on children, education and health, though Zuckerberg is also active in immigration reform. Last year, he and other tech leaders formed Fwd.us, a political group aimed at changing immigration policy, boosting education and encouraging investment in scientific research. Through Facebook, he's also spearheading Internet.org, which aims to connect the more than 70 percent of the world's 7 billion people who are not yet online.
Connecting the world and children: That's the stuff of dinner conversations in the Zuckerberg-Chan household. A child of Chinese immigrants who arrived in the U.S. on a refugee boat, Chan recalled an early memory that shaped who she is. It was the time her mother left to give birth to her younger sister and she was left with her grandparents.
"I remember thinking when my mom was absent that it's my turn to step up and care for my grandmother and my grandfather, and I've carried that with me ever since," Chan recalled. She was two and a half at the time.
Zuckerberg, who turned 30 earlier this month, said he and Chan are inspired by Bill and Melinda Gates and others who believe philanthropy "isn't just something where you can wake up one day and decide to give away a bunch of money and do it effectively. Like anything else, you need practice."
To help prepare for their charitable work in education, Zuckerberg and Chan decided they needed hands-on experience. Chan has taught 4th and 5th grade science at a local private school and Zuckerberg has run an after-school program on entrepreneurship.
"We talked about the education work that we wanted to do and she made this point to me that I wasn't going be one of those people who (try to help by giving) money to places but had never taught anything myself," Zuckerberg said. He didn't think he'd have time to teach while running Facebook, but Chan set it all up. He says, "it actually ended up being awesome." He still meets with the students regularly.
All the talk of children leads to talk of kids of their own.
"Well one day...but right now." Chan said.
Zuckerberg cut in, "That's a yes," to laughter all around.
"Yes, but, we are a little preoccupied with other people's children right now," added Chan.
Reach Barbara Ortutay on Twitter at https://twitter.com/BarbaraOrtutay