elearnspace.Connectivism: A Learning Theory for the Digital Age:
by George Siemens
Great read for all interested in ICT and education.
Here is the introduction, follow the link on the top to read the rest of this article and more on elearning:
"Behaviorism, cognitivism, and constructivism are the three          broad learning theories most often utilized in the creation of instructional          environments. These theories, however, were developed in a time when learning          was not impacted through technology. Over the last twenty years, technology          has reorganized how we live, how we communicate, and how we learn. Learning          needs and theories that describe learning principles and processes, should          be reflective of underlying social environments. Vaill emphasizes that          “learning must be a way of being – an ongoing set of attitudes          and actions by individuals and groups that they employ to try to keep          abreast o the surprising, novel, messy, obtrusive, recurring events…”          (1996, p.42).        
 Learners as little as forty years ago would complete the          required schooling and enter a career that would often last a lifetime.          Information development was slow. The life of knowledge was measured in          decades. Today, these foundational principles have been altered. Knowledge          is growing exponentially. In many fields the life of knowledge is now          measured in months and years. Gonzalez (2004) describes the challenges          of rapidly diminishing knowledge life:
                  “One of the most persuasive factors is the shrinking            half-life of knowledge. The “half-life of knowledge” is            the time span from when knowledge is gained to when it becomes obsolete.            Half of what is known today was not known 10 years ago. The amount of            knowledge in the world has doubled in the past 10 years and is doubling            every 18 months according to the American Society of Training and Documentation            (ASTD). To combat the shrinking half-life of knowledge, organizations            have been forced to develop new methods of deploying instruction.”