Billionaire philanthropist Bill Gates has many personal passions. Among them are the eradication of malaria, childhood healthcare, and—of course—education.

Tuesday (Mar. 8), Gates offered some fresh thoughts on the future of schooling in an “Ask Me Anything” Q&A session on Reddit. A user posed the following question:

Hello Mr. Gates,

You have previously said that, through organizations like Khan Academy and Wikipedia and the Internet in general, getting access to knowledge is now easier than ever. While that is certainly true, K-12 education seems to have stayed frozen in time. How do you think the school system will or should change in the decades to come?

Gates responded with candor. “I agree that our schools have not improved as much as we want them to,” he said. “There are a lot of great teachers, but… most teachers get very little feedback about what they do well.”

While technology is “starting to improve education,” he said, it’s not personalized or focused enough to truly help teachers figure out how to improve. And most educational technology thus far has benefited only the most motivated students, he said, not those who need extra encouragement most.

Added Gates, “A lot of the issue is helping kids stay engaged. If they don’t feel the material is relevant or they don’t have a sense of their own ability they can check out too easily. The technology has not done enough to help with this yet.”

While more teachers say they welcome technology, most gadgets and digital techniques haven’t shown they can boost learning. Many schools have abandoned using iPads, for example, and online learning has yet to live up to its promises. Silicon Valley will have to do better yet if it’s going to make a genuine difference in the classroom.