How learning is measured?

Learning is usually measured by a diagnostic test; i.e., a test of materials that fall under a certain subject or discipline, administered to students who have studied that subject. The scores are ranked and an average found. If you fall in the average percentile (50%) or higher, presumably you've learned something.

On the other hand, knowledge, which is usually determined by how much information you possess about a certain subject, is more abstract than mere learning. The knowledge you possess within or concerning a subject or discipline is usually indicated by the kind of work you produce within that subject: an experiment, a published article or book, and so forth.

Your question could be better answered if you were more specific about what you really want to know: academic preparedness that demonstrates the extent of knowledge of a certain subject (diagnostic test) or true possession of expertise within a discipline.