(Revised October 15, 2007)
Tagging becomes popular with the prevalence of Web 2.0. A tag is a keyword or term bound to a piece of information. By default, a tag is assumed to be a correct partial explanation of the bound object. This explanation is unnecessary to be complete, and it is also unnecessary to be about the key characters of the bound object. The purpose of tagging is primarily to associate web content to human conventions.
From the view of web evolution, however, we have another explanation of this Web-2.0 tagging. By this view, tagging is a process of drawing threads across the Web. The activities of tagging convert the traditional node-driven web to be a new thread-driven web; this is a prediction based on web evolution.
Node-driven Web versus Thread-driven Web
A node-driven web is a web whose structure is primarily driven by how web users link their authored web nodes to each other. Albert-Laszlo Barabasi had made great contributions on this field by studying the so-called scale-free network, which is typically node driven. Whenever a new node is added into a node-driven web, its owner decides how to connect this new node to existing ones. This type of decisions is, however, often not random. In contrast, people always tend to link a new node to the most popular node existed in the current web. The chance that a less popular node gets a new link decreases exponentially to its popularity. This theory is fundamental to the growth of node-driven webs.
Web thread is a new term. In my mind, a web thread is a connection that link various multiple web nodes to a fixed inbound. Unlike a standard web link that connects exactly one outbound node to one inbound node, a web thread may simultaneously connect more than two web nodes omnidirectionally. For example, a Web-2.0 tag is a web thread. Other than linking from one node to another, a Web-2.0 tag simultaneously connects arbitrary numbers of web nodes that share the same tag. This is why we call it a "thread" but not a "link" on the Web.
A thread-driven web is a web whose structure is primarily driven by the interconnections of web threads. When a new node is added into a thread-driven web, the web itself automatically decides how to locate this new node by assigning proper threads to it based on the content in this node. Although we do not prohibit user-specified links or threads, the popularity of a web node is determined by the richness of its content (i.e. how many threads are weaved through this node) instead of the number of human-specified links connected to this node.
The popularity of web nodes in a node-driven web is primarily decided by the votes of humans. The most popular hubs in a node-driven web may not necessarily contain rich information themselves. For example, the homepage of Google is just a simple interface without much information. But humans subjectively decide that these hubs are more valuable than many other web nodes.
In contrast, the popularity of web nodes in a thread-driven web is primarily decided by the richness of content in these nodes. The most popular hubs in a thread-driven web may not necessarily be favorite sites for most of the human users. But these nodes definitely contain richest information on the Web for machines to process.
With this comparison, we can see that a node-driven web is human-oriented while a thread-driven web is machine-oriented. If the future is Semantic Web, the Web certainly is evolving from a node-driven web to a thread-driven web. To machines, the popular human favorite sites such as the main page of Google is less valuable because it does not really provide much useful information. In contrast, machines look for nodes weaved by the most number of threads that concentrate on their searched topic. This switch of vision on World Wide Web may eventually change the methods of web search in the future.
Some Potential Impacts to the Future
This re-interpretation of tagging may bring us several positive impacts on developing next-generation web technologies.
(1) This re-interpretation brings us a new picture of World Wide Web. World Wide Web has gradually turning from a random network to be a more and more well-organized network. Before Web 2.0, the model of World Wide Web is widely known as a scale-free network formally introduced by Albert-Laszlo Barabasi. This new interpretation, however, states that underneath the scale-free architecture, World Wide Web actually maintains a fairly organized latent structure, whose backbones are web threads. A scale-free network is significantly dominated by few highly connected hubs. A well-organized thread-driven network, however, is dominated by highly adopted threads. This crucial difference between the two network architecture is a key of developing next-generation web technologies, especially the next-generation web search techniques.
(2) This re-interpretation brings us a new understanding of what web tags are. Web tags are not standard web links. When we produce a new web tag, we are producing a new thread of World Wide Web. The popularity of these threads, however, are determined by their acceptance among web users. On the other hand, the popularity of web thread may still follow the Yule-Simon distribution---a power law relationship, as what the scale-free model follows. These thoughts might be helpful for the further study of web tags and threads.
(3) This re-interpretation suggests us a new way of building a semantic web. Instead of creating semantic-web nodes (as we are creating normal web nodes), building a semantic web is creating web threads and throwing these threads across a network. By weaving these threads, we acquire semantic-web nodes by their intersections.
(4) This re-interpretation brings us a new vision to personalize World Wide Web. Based on this view of thread-driven web, a personalized web becomes a web weaved by personalized threads. By delicately mapping personalized threads to widely adopted threads, we can produce personalized web for individuals. In return, these personalized webs become latent chaos patterns of the entire World Wide Web.
Tuesday, July 31, 2007
(Revised October 15, 2007)