Grading/correcting/? assignments
If you are making corrections for the students, you are "correcting" their papers.
If you are only pointing out which of their responses need to be corrected, you are "reviewing" and "marking" their papers.
If you are making corrections for the students, you are "correcting" their papers.
If you are only pointing out which of their responses need to be corrected, you are "reviewing" and "marking" their papers.