I want to know the answer to the following question:
How many classes of research does Woolf encourage?
All the background I'm provided with is that "Woolf suggests three classes of pain : (1) nociceptive pain, (2) inflammatory pain which is associated with tissue damage and the infiltration of immune cells, and (3) pathological pain which is a disease state caused by damage to the nervous system or by its abnormal function (e.g. fibromyalgia, irritable bowel syndrome, tension type headache, etc.).". Is that enough to answer the question?