The process of innovation involves getting new ideas accepted and new technologies adopted and used. There are a number of different approaches to theorising technological innovation and this chapter will compare and contrast what I suggest are the most important three: Innovation Diffusion, the Technology Acceptance Model (TAM) and Innovation Translation, giving examples of how each of these approaches is used in different situations. While there are many advantages to the use of an Innovation Translation approach, it should not be said that Translation offers a better approach than the others in all circumstances and that the others have nothing at all to offer; that would be rather too simplistic a view given the widespread use of Innovation Diffusion and TAM. This chapter proposes that perhaps it should not be a case of always using either one approach or the other but rather the use of whichever is most appropriate to a particular investigation.