I think of those six three are most relevant to our on-line interaction. Those three are, presence as social richness, presence as transportation, and presence as immersion.

Social Richness points to the number of cues we get from a medium, and relates to the Media Richness theory, that combines it with the medium's characteristics.

Presence as Transportation looks at what the medium does, does it transport you to somewhere (for instance a fantasy novel that brings you to another world), does it bring something to you (like newsbulletins that bring the world to your doorstep), or does it create a place where people come together. It is the last version that is most relevant to knowledge workers; bringing people together for interaction, but both others are part of the picture as well.

Presence as Immersion has to do with how much of you is involved in the communication through a medium. This closely connects to Flemmings posting about being in the here and now. Does a medium succeed in letting you concentrate entirely on it, or does it allow for distractions etc.

As Elmine alludes in her recent writings on how media facilitate for conversation and discourse:

no single medium can offer a platform for discourse, so weblogs as a sole medium can't be seen as discourse. Rather, weblogs are a very good startingpoint for discourse. The weblog can serve as a filter for getting to know people who are interested in the same things. Through weblogs one can have conversations with 'self' and (preferably) others. These conversations can transcend into discourse when people start using multiple communication tools simultaneously (VoIP, chat, forum, e-mail, wiki, webcam etc.), and ultimately start meeting eachother face-to-face.

If no single medium can satisfy all our requirements to reach a high level of presence, that can cater for our need for discourse, than we need a mix of media to compensate for the shortcomings of any one medium in that mix. Elmine, in my view rightly, suggests that a blog is a very good starting point to present the available media mix to potential conversation and discourse partners. It serves as a fixed marker, that contains enough context to build trust and start a relationship through conversation. It also allows you to provide access to other media (e-mail, wiki, Skype, IM, video, documents etc., contact info for face to face) that can build on the conversations started at the weblog, but in themselves are more fluid which makes using them as a permanent marker less useful. Weblogs are much richer fixed markers as for instance profiles at fora, or YASN's, since they are fixed markers in location, but not fixed in content. Our weblog can serve as our Personal Presence Portal, the hub in our communicational flow.

Media Mix

What a lot of us try to do either with blogs or through a wiki, or whatever other medium we use on-line, is to open up space for conversation, dialogue, discussion, and discourse. We tend to bet everything on one horse though, expecting (and often evangelizing as well) that all our needs are served by one medium. Every medium has aspects that serve our purposes well. Blogs create context and thus help build trust, wiki's open up possibilities of collaboration, fora cater to discussions, e-mail to extended conversations, etc. etc. But as I argued in the previous paragraphs, a mix of media is needed to cater to the different factors in building a sense of presence.
In the following table I try to connect the different media to the different aspects of presence. For this I also refer to this piece by Dave Pollard, and this one by Zbigniew Lukasiak

[NOTE: I will add in the table with media later on. No time to do it now, but did not want to wait with posting either, so read the text first, you can do without the table for now]

If we know, and I think, intuitively we all do, that it's a mix of media that serves us best, then why don't we exploit such a mix to it's utmost limits?

Awkwardness
Dave Pollard, somewhat in frustration, asks why it often feels so awkward to start using different media with other people. And apparantly it is this awkwardness that keeps us from using the full mix of media at our disposal.

The awkwardness we feel stems from the difference in richness of media, I think. When I move on from a text based medium like blogs or e-mail to a voice oriented medium, the information richness increases. We get to know more about eachother, but requires that we show ourselves a bit more as well. This might not be a conscious thing, who explicitly is aware that our voice gives away more clues as to who we are then our written words. And when you switch media, you don't know if the other will be welcoming the attempt.

Now when you meet someone in person, there is that same awkwardness, but it is dealt with more or less unconsciously by us. When I picked up Jon Husband, or Flemming Funch from the railway station when they came to stay with us, it was strange to meet a stranger, based on blog-interaction and some short phone calls confirming times of arrival. But our bodies deal with that awkwardness. We look around uncertainly for the other, whom we don't know, then we smile to test whether we found the right person, and we greet eachother. We see eachothers uneasy start, and perceive we are on equal footing in this social interaction. Then the conversation starts, and we manage past the awkwardness.

Stepping 'down' from a face to face meeting to other media is no problem. But stepping 'up' without previous personal encounters is more difficult: we do not see our own awkwardness reflected in the other's body language. To get across it we have to make our awkwardness explicit, since we have no backchannel to deal with it in a more unconscious way.

So to end the awkwardness we might learn to say it out loud during a first video conference, or first skype-call, that it is awkward but exciting at the same time. And that will then launch us into conversation, is my guess.