The questions of quality may be divided into four distinct classes, namely, ontological, epistemological, value-theoretical, and pragmatic. However, there are plenty of important problems to the solutions which have bearings on the different classes. Some of the problems are very tricky, and we shall explore two of them: (1) How does the basic ontology affect the form and content of the resulting conceptual model? and (2) What is the status of formalization in pragmatics? There are good reasons to believe that the answers to these two questions may also answer the other ones.