Glad to have you in this forum and I'm interested in your work to measure learning outcomes. I've been involved in this type of work as well and always look for collaborative opportunities. In my work, I've gotten some benefit from the concept of an assessment triangle, in which a model of student cognition is used as a basis for measuring outcomes (check out link below). Have you had any success in articulating such models to measure learning outcomes? Seems like these models would be a great way to foster cross-institutional collaboration.
Knowing what students know http://www.nap.edu/openbook.php?isbn=0309072727