A brief history of the social web between two people, and trust are two relationship features that have great impact on what happens in a social network. Furthermore, learning what role a person plays in a network by analyzing his or her behavior can link quantitative measures with qualitative analysis to help better understand what goes on in a social group.
Visualization, which is the creation images like Figure 1.1 that visually represent the structure of a social network, allows us to leverage our natural abilities to per- ceive patterns in images to better understand network structure and patterns.
With those analysis methods at hand, the next step is to use them to understand network phenomena. One of the most important of these phenomena is propagation: How do things like information, diseases, or rumors spread in a network?
A combination of quantitative and qualitative features inform our understanding of propagation, and another set of analysis techniques is available to study the spread of things through networks.
Throughout the book, we will use real social media networks to demonstrate the techniques described above. But understanding social media goes beyond these types of analysis. The second half of the book will look at specific questions of interest to different types of social media. For example, what motivates people to contribute to Wikipedia?
How do politicians leverage social media to spread their messages or communicate with constituents? How do businesses make decisions about when to use social media? What privacy threats do users face in these websites?
To answer these questions, we will apply the techniques from the first half of the book and described above, and present the results of research and experiments to show the full range of analysis used to understand the many issues related to social media.
A brief history of the social web
The web was invented in 1991, and from the start, Tim Berners-Lee, its inventor, saw it as a place where people could interact. He called it "a collaborative medium, a place where we all meet and read and write."
At first, authoring web content required people to learn HTML, the language used for all web pages. Putting pages online also required access to a server and some technical knowl- edge that was a barrier for casual web users.
There were some ways to interact—chat rooms and discussion forums existed even before the web—but overall, the web was a place of static web pages that users simply visited. Blogging began in 1997, and the website Blogger (now owned and operated by Google) went online in 1999.
Not only did this allow users to gen- erate content without any knowledge of HTML or other programming languages, but people could comment, thus allowing interaction online. Users could also fol- low each other's blogs, which created a social network behind the content.
The first site to launch in the spirit of modern social networking sites was Six Degrees. It went online in 1997 and allowed people to create profiles and list their friends. At the height of its popularity it had one million members.
Blogging and other interactive web technologies continued to grow through the millennium as the dot com era boomed and after the bubble burst. While some sites failed, some current major social media sites emerged.
Friendster launched in 2002, which grew quickly and was the first major social networking website. It was followed by LinkedIn (a business-oriented network) and MySpace in 2003. MySpace was the social network that largely brought online social net- working into the public consciousness, and it reigned as one of the most popular networks for several years.
Facebook followed in 2004. It was first restricted to students at Harvard and a set of elite universities, but eventually expanded to all colleges and then the general public. It is currently the largest social networking website, with over a billion users.
