I have taken CS 6604 “Digital Libraries” last semester. Can I take the “Tools for Online Education” course next semester which also appears to have the same number CS 6604?
You can always take courses. You are probably enquiring if both of them can count toward your plan of study. The answer is “yes”. Most 6000-level courses in CS are advanced topics courses. As the catalog description in the graduate handbook says, this course “treats a specific advanced topic of current research interest in the area of data and information.. May be repeated with different content for a maximum of 12 credit hours.” So, not only can you take CS 6604 again, you can take it again two more times!