Hi Jeffrey,
Something I have used with good success is a "one minute" paper writing exercise. The students have one minute to write on a topic, I generally have them write on their career goals or why they selected the career field they are in. The one minute writing effort doesn't take long and doesn't create stress for the students. I read their papers and this gives me an accurate picture of their comprehension, writing and expression abilities. This gives me a place to start in creating my assignments around their needs.
Gary