My son came home and said, 'Teacher made us do a peer review.' I said, 'That builds critical thinking. What did you write on your friend's paper?' He said, 'I wrote, This is fine. And then I wrote, I don't know what this means, but it's fine. And then I wrote, The last sentence is about a dog. The rest is about a cat. I don't know how a dog got in there. I'm flagging it.' His teacher said it was constructive feedback.