The conversational education method does have some drawbacks.
I asked for input, and both 9th graders decided they'd rather do an in-depth earth science unit before tackling biology. OK. No problem! Their friends are doing earth science, so it'll be a group effort. We began by discussing places we've been with obvious geological learning opportunities.
"That copper mine!"
Then, things turned ugly...
"My copper bracelet broke. It needs a new clasp."
"You know, Libby took my copper earrings and never gave them back..."
"Yeah, well, you borrow stuff of mine all the time..."
At that moment, Trip called for a ride home (he only had one hour of school today). Saved by the bell; I'm going to the beach.