  This paper tries to contribute towards the solution of an important question
raised in the SE literature: What is a Software Engineering (SE) specific
theory? Which are the main features of a theory that is endemic to SE? In this
paper we will use 'theory' as the term is used in traditional sciences. Other
uses of the term 'theory' are discussed. Finally, we propose to focus on the
reference class and on the structuring of SE theories as a basis for further
progress.
