Harkness is definitely not for everyone. You have to pick the school and type of teaching carefully. For someone who participates regularly and likes to engage all the time, it might be great. Others like to absorb their learning. My kiddo really likes Harkness but said it’s tough in some classes where teachers try to get the kids who don’t speak much to engage even though they might not be that interested. For sure, there is no room for anyone missing homework or working in class. The teacher will catch it quick in a group of 5-12 students. Can be a great way for kids to learn about college courses esp if they pursue a small liberal arts class.
Math and science classes are often not Harkness for obvious reasons. Math teacher told us, he let our kiddo put another solution on the board at the same time so the two results could be compared. I really liked that approach.