<qa>  What is the purpose of this study?One way to better understand how various treatments for pain differ is to determine the effects of these treatments on different pain qualities or characteristics. For example, pain can be described as hot, electrical, cold, achy, and piercing. In order to determine which pain qualityqualities that a pain treatment affects, researchers must develop measures of these pain qualities or characteristics. The purpose of this study is to learn more about the different pain qualities individuals who have low back pain, headaches and fibromyalgia experience. Identifying the common qualities of pain experienced by these groups will help researchers evaluate and develop more comprehensive pain quality measures, which will ultimately help them to be able to test the effectiveness of treatments for these different pain qualities. 