IJsselsteijn also makes the following observation about the future: "With more advanced media, it will become increasingly hard to adequately recognize the role of technology in the experience. People will need to make increasingly sophisticated judgments about what is real and what is not." (IJsselsteijn 2004, 165). The fact that the better presence is mediated the harder it is to distinguish real from unreal presence, is problematic for our living together. The possible confusion between real and unreal, between here and there, between now and then, between you and someone else, between man and machine, is also part of the motivation that drives this study. To understand the trade-off better - not only within mediated presence, but also between natural and mediated presence in the construction of communication processes of social interaction - I distinguish between three kinds of presences in the following sections. The distinction between these three kinds of presences is based upon the sketch of the current presence research as well as on the description of the presence technologies earlier in this chapter.
The first kind of presence I will elaborate upon is 'natural presence', which is characterized by being physically alive. Our natural presence can be 'mediated' by technologies, we can act and connect at a distance. Therefore, 'mediated presence' is the second concept I will discuss. Thirdly I will introduce the notion of 'witnessed presence', as a phenomenon that needs attention in its own right. Because of the descriptions of the presence technologies, in which the concept of 'being witnessed' characterizes some of them from the viewpoint of the person being witnessed, I choose to include 'witnessed presence'. Witnessing is an action that people perform on each other and it has an effect on how people orchestrate their own presence and therefore it influences interaction. Witnessed presence, which includes witnessing as well as being witnessed, plays a significant role in natural presence as well as in mediated presence when discussing social interaction.