The term 'theory' is often used with little regard for its precise definition. Within the discipline of marketing the term 'theory' is often applied to the concept of the adoption process. However, the validity of terming this concept a theory has not been rigorously tested. This paper addresses this issue by applying metatheoretical evaluation criteria to the adoption process. The objective of the paper was twofold. The first objective was to outline a theory formalisation framework and to detail the criteria any proposed theory must meet prior to an attempt to fully formalise that theory. The second objective of the paper was to use a selection of evaluative criteria and apply this to the adoption process. This paper identifies the adoption process as weak in many areas of the evaluative criteria and, accordingly, it is concluded to have limited validity as a theoretical construct.