Classic IR (information retrieval) is predicated on the notion of users searching for information in order to satisfy a particular ‘information need’. However, much of what we recognise as search behaviour is often not informational per se. In this presentation, we examine the behaviour of individuals across a range of site search scenarios, and define a taxonomy of fundamental behaviours or 'search modes'. We compare these with a comparable set of modes derived from the domain of enterprise search, and examine some of the key differences between the two. We also discuss some initial implications and techniques for the design of more effective site search experiences.