You're a college professor. One of your students struggles with writing and typically does not turn in high-quality papers. Halfway through the semester, you notice that the quality of his work dramatically improves. You suspect that he may be plagiarizing, but you are unable to find any evidence that the work is not his own. How would you handle this?

a. Say the student was on probation and would certainly be expelled if he were found guilty of plagiarism. How would this affect your course of action?