Alan, I mean the entries that say someting like "please correct the sentences below" and lists10 sentences, numbered 1-10 that looks like a homework assignment. For others, i get the sense I am correcting a paper they will hand in for a grade. 

If they make an attempt to anwer the questions and reflect on the answers, that is fine. Yet cut and pasting a class assignment, having a native do the work and turning it in is not appropriate.

"Most entries/questions look like the student wrote the text or has questions about pre-written text"

I'm honestly not sure what you mean. Notebooks are meant to have been written, they're writing practice! And cut/paste is totally appropriate in Questions when a learner has a reading comprehension question.

Jack makes a good point. Correction alone is pretty useless unless it makes the learner reflect on their weak areas and practice more to improve them.