As part of thinking about how to create comprehensive visualizations of someone's online history, I did an informal survey of the sorts of visualizations (broadly interpreted) that already exist. I've included a representative set of what I found here, along with discussion. The included examples are loosely ordered by the weight of the social signal attached, starting with those visualizations that can be created with very little cost, ending with those that represent a substantial time investment on the part of the user.
People use these tags in a variety of venues (signatures, profile pages, etc) as a lightweight way to show involvement in a specific group. In the case of the example included above, this person wants to show their commitment to a variety of product brands, software tools, video games, and their nationality. These tags are not particularly interesting. There are huge web-baesd repositories of these tags that share a common aesthetic, so it's quite easy to assemble a new set. Moreover, the tags don't contain any sense of history - how long someone has had that particular tag.
The expansion of online communities beyond Usenet enabled a wide variety of ways to represent identity within a particular context. These two examples show some common ways this is handled. Post count and join date are two of the most common ways to represent someone's involvement with a particular community. Between these two numbers, it's easy to get a sense of how prolific someone is by looking at (approximately) their posts per unit time. Forums also often give users the opportunity to select graphical avatars. These avatars are sometimes used as pictures of the person in question, but they are more often images selected to convey something more general about that person's personality. Forums can also provide more structured ways to describe identity, as in the examples above that provide a space for specifying someone's "team". In this case, these team identifiers are quite relevant and more closely tie this particular community to offline activities - FIRST robotics competitions in this case. All of these features are limited to a specific community, and so are ultimately a one dimensional representation of that person's identity. Information like post-count and date joined provide only limited resolution about the kind of involvement someone has in a particular community.
There are a variety of services on the web that make it possible to embed a more or less up to date representation of some facet of data about their lives. In these examples, that data is recently played songs, progress towards a particular personal goal, and current location. This style of information is quite interesting, and points towards the value of having visualizations that are frequently updating. In the case of the songs image, it's quite interesting that the designers chose to display the most recent songs, not the (heavier and probably more significant) most played songs. There is certainly value in both approaches, but I think this is an important lesson in the value that recent information has over old and infrequently changing data. A visualization that could elegantly combine both of those types of information has a lot of promise.
These three examples are from a single forum, in which members of the forum can pay real money for small icons and badges. This is kind of clumsy, but it certainly makes them much more meaningful than the earlier examples. The icons below the image-avatar can be one to one mappings of certain aspects of their personality, expressing their preference of different genres of games. They can also be used, as in the second example, for mostly aesthetic reasons. This flexibility makes them particularly interesting. The "supporter" indicators are also quite excellent because they offer limited edition tags that indicate someone's long-term involvement with this forum.
As del.icio.us became popular, a certain visualization style quickly emerged. One of the earliest examples is the ex.ti.pcio.us tag cloud visualization (shown above) in which a particular user's tags are arbitrarily mapped into the space and their font size is scaled to represent the frequency of each tag's appearance. This style is interesting in general, but since it's only really making use of one axis (font size) it's ultimately not that effective. It did act as a proof of concept of a personal online history introspection tool - lots of people (myself included) were really interested to see what their tag cloud might look like. There was no built-in way for users to spread their tag clouds, though. It's unclear whether or not people would be interested in sharing them.
Because the limitations of the first tag clouds were pretty clear, other people quickly developed more complex versions. The one shown above changes in a few important ways. The layout of words in the x-y plane is a function of their joint appearance on particular saved links. This provides some basic semiotic structure; we see certain areas (like HCI) that this person is interested in with much more subtlety and detail that in the previous example. This version also has much better handling of typography, making sure even the most infrequently used tags are still legible. Color is also used to reinforce the frequency of use.
This final example is interesting mostly because of where I found it. This image was part of an image signature on an email that also included the person's contact information. It's a great example of more or less how I'm imagining Chatterprint images will ultimately be used. While it's not substantially different in content from the first tag cloud, it's generally well executed in a way that makes it particularly legible and concise. It still suffers from the one-dimensionality of other tag clouds - it only includes information from one source, and doesn't seem to include any meaning in the layout.
Avatars have long been part of the vision of online spaces. There are lots of examples of avatars in 3D spaces, but fewer examples on the web. Still, there are a number of forums that incorporate avatars as a central element. I discuss two of those sites here.
Most avatar based systems create a system in which different items to adorn the avatar cost different amounts of money. In this first example, the operant currency is "blessings", shown on the right side of each post's header. Users of the forum can accrue these currencies through various means (like forum involvement) and then spend them on different clothing items. This site also offers "pets" that users can adopt and care for. Besides the avatar, this site also uses small badges much like Board Game Geeks (discussed above), but only in the literal "this badge represents something particular about me" sense. In this case, they are used to represent political orientation, religious affiliation, and marital status, among others.
This avatar is broadly similar to the first two, but comes from a site with a more involved economic system around its avatars. In general, avatars are a good tool because they provide both a venue for self expression as well as an easy way to tell long-time users from recent joiners in a much less literal way than listing the number of posts or join dates.