I'm finding that making them discuss the lab on video really helps them to go back and think about their ideas so they can work on writing results and conclusions during the next class. Here are J and J discussing their experiment with the team (and myself):
I also really like the idea that students see that results aren't exactly the same as other groups. I've actually had groups that thought they had "messed up" because the results weren't precisely the same. We always take final pictures of the lab so we can include it in our write up and also put it into draw tools and label examples of vocabulary so they have another visual aid for the words in the definitions. Sometimes they get competitive with how many terms they can label with their picture.
I do have to say that after working in a couple of districts that use these kits, I am always surprised by the number of teachers who don't use them with their students. My kids get such a kick out of performing these experiments, and then we'll use the guided experiments to develop our own questions, and figure out ways to test them. I think with the NGSS the testing of their ideas is something they are going to have to deeply understand so they can analyze test questions for pitfalls and strengths.