 So I have been using OER in my classes since the fall of 2019. We shifted our general chemistry to a version of open stacks that I had curated and was hosting on Libra text. So we already had that and what I've been trying to do since about that same time is get OERs in my upper-level classes. I teach two upper-level classes in environmental chemistry, the fate and transport of pollutants that I already mentioned, and an environmental chemistry, analytical chemistry, toxicology type deal. But there aren't good open resources for specialized upper-division classes, because they're just so specific to those topics. So what I started using Hypothesis for last year, in that respect, I went to the OpenEd conference, the OpenEd 2020 conference, and I saw a really good presentation about having students tag their readings with these very specific keywords that we have definitions for. And that's what I've been having them do when I assigned them. So basically I've been assigning them parts of other OERs and having them go through and tell me what they think is important to then build the OER from using these tags, or what they think could be made more clear, like this explanation is muddy and it would be better if you rewrote it sort of thing. So I've been doing that in my environmental chemistry course. This year I'm teaching a new and different general chemistry course. I'm building the OER again and I'm having the students, when they do their reading assignments, instead of it being a reading quiz, their assignment is to go through and tag the open-stacks chemistry sections that we're covering to help me build the next general chemistry OER for the course.