A couple of times now I have discussed the idea of Personal (or professional) Learning Networks (PLN) with people on Twitter. Some have questioned what they actually are, if they really exist, and whether or not they are really new or not. I won't try to quote (or misquote) others here, but hopefully they will weigh in with their comments.
First of all a PLN is defined in wikipedia as:
Personal Learning Networks consist of the people a learner interacts with and derives knowledge from in a Personal Learning Environment. Learners create connections and develop a network that contributes to their professional development and knowledge.  The learner does not have to know these people personally or ever meet them in person.
I don't know if this is a perfect definition but it is a starting point. I like the fact that it is broad rather than specific. I would like to share my opinion about what a PLN is and argue that it does exist.
My PLN is all of the people that I learn from. First of all, it is the many mentor teachers and colleagues in my building and district. They have helped me with classroom management, lesson plans and ideas, and listened when I have had a difficult day. Next it is people that I learn from digitally through internet sites or tools. My two favorite sources of interaction are blogs and Twitter. Others use sites such as Facebook, Nings, Skype, email, Plurk, wikis, and even Google Buzz or Wave. In the past people used databases and listserves. The tools really don't matter and five years from now we will probably have a whole new list of them. I really find little benefit to rank which of these tools are better, but think that each learner should play and discover which tools best help them connect.
These learning relationships have existed since ancient times, but the reason that we need a new term for them is that the digital version of them is relatively new, and I would argue different than the past. In the past one had to become a disciple of Socrates, Jesus, or Budha and physically follow them around. This limited the number of people who could commit to this lifestyle. With books one could learn from a distance from the greatest minds of the past and present. But books can not answer questions. (There is an internal dialogue between author and reader, but again I think that is different from on-line conversations between multiple participants). Personal relationships have always been a part of learning and always will be, but...
What we have in digital networks are expanded relationships between people who would never have been connected in the past. I can learn from other teachers, administrators, professors (without having to pay for their class or travel to their university), student teachers, and students from around the world at the same time. That is what is different-direct and instantaneous access to thousands of minds from every corner of the earth. The learning I experience is exponentially more than what I can learn from the teachers in my building or district alone.
In the past there was a danger of tunnel vision from only learning from those "near" you. Now I can interact with great minds with multiple perspectives whenever I want. My digital network is always available for me to learn from 24/7. It is never off and takes no holidays (It does celebrate them though). There are a few people who do not reciprocate conversations, but the vast majority of people in these on-line spaces will talk to anyone. Therefore I do not see PLN's as exclusive at all. I did at one time, but have found that if you engage with others than they will engage back.
Another new thing about PLN's is that although I would argue they are personal in that each person creates their own relationships through their own choices of tools and contacts, it is not limited to just the connections that you make. Countless times I have asked for help with a resource or problem on Twitter and it has been re-tweeted and answered by people that I have never "met" online or even heard of. I think of this as the Kevin Bacon effect in that I benefit from the relationships of people in my network beyond my own relationships. This multiplication effect is very powerful. Also most of the on-line tools allow for "lurking" so that people can learn from listening too.
Is this new? Not all of it, but I think the instant, public discourse of leading thinkers is. Also the ability of anyone to engage with anyone without having to apply, go to a conference, be accepted into university, or buy their book is. Anyone can be a virtual disciple from some excellent education leaders.
The last point I would like to make is that I think people in the on-line communities forget that the vast majority of teachers are not part of an extended, on-line PLN, but are limited to their physical relationships and the few books that they read in a grad class. Therefore I would argue that we NEED some kind of term for what "this" is to help define it for those not in these communities. Is PLN the best term, maybe not, but it is the accepted one at the moment until someone comes up with something better. So I am not committed to the term PLN specifically, but what it represents is very important to me.
OK let me have it, what do you think?
Wikipedia footnote a b c Connectivism: A Learning Theory for the Digital Age, International Journal of Instructional Technology and Distance Learning, Vol. 2 No. 1, Jan 2005