For those of us who have spent a number of years working in online learning, the idea that a group can collaborate asynchronously (not in real-time) on a learning activity is rather taken for granted - not so much 'old hat' as just nothing novel. But in the grand scheme of things it's a relative newcomer and - as is becoming increasingly apparent as I talk to those learning professionals with no online experience - not an obvious thing to do.

Historically, all social learning activities, whether one-to-one or group, would have been synchronous (real-time). Furthermore, because until recently there were no technologies to mediate this process, they'd also have been face-to-face.

On the other hand, asynchronous learning in centuries past would have been individual and reflective.

Bit by bit, new technologies enhanced these processes. Asynchronous self-study was supported first by books and then, in the twentieth century by all kinds of tapes, discs and films. But individual it remained.

Synchronous learning also benefited by technology; first the telephone and then online tools such as text chat, instant messaging, internet telephony and web conferencing.

All very good, but the model remained synchronous = social and asynchronous = individual.

Only in the past 20 or so years has it become possible to engage with others on a learning activity without setting a date and time that was mutually agreeable. And 20 years is, in the history of learning, no time at all. I suppose you could argue that learners could have interacted with tutors by post, and of course that's has how the original correspondence courses worked. Similarly, I suppose, groups of learners could have collaborated in the same way. But was this normal? No. Was it sufficiently speedy and flexible to be desirable? No. It was a last resort.

So what does it mean to be able to interact, as learners, using email, forums, wikis, blogs, social networks and the like? Quite a lot I reckon. There are considerable advantages to asynchronous learning:

• It allows time for reflection.
• It isn't dominated so much by those who speak before they think.
• It allows for more in-depth research and sharing of perspectives.
• It allows learners to control when they participate and for how long.

And when that asynchronous learning is online as opposed to by snail mail, then the practical barriers break down:

• You can post messages just about instantly.
• You can share large volumes of content in a wide variety of forms.
• You have a record of all interactions that can be viewed by all participants.