A mix of things. Multimodal composition is assessed as part of our first-year writing portfolio assessment procedure; undergraduate majors' work is assessed as part of our department's portfolio assessment procedures.

some "literacies" and literacy outcomes are recommended by program committee, it is largely left to individual instructors to design and implement assessment tools.

It varies from course to course, program to program.

The Writing Center doesn't "assess" multimodal texts; we provide constructive feedback, both rhetorical and technical.