The more time I spend surrounded by mobile learners, the more this question comes back to haunt me. We have used many different approaches and devices already, but still the issue is FAR from simple.
There are a wide spectrum of strategies. At one end we have learning that is VERY device specific - exploiting what each device does best. At the other end is data-pushing, where we have some central resources that get intelligently reformatted for multiple different devices.
But which is best?
Evolving standards for data push us towards the data-push area. I can see the same RSS feed on many different devices. My smart content system will reformat a powerpoint to run on many different devices. A lo of energy has been invested in perfecting data-push, but is that really enough for learners?
At the other, device specific end, think about simple mp3 players. All they can do is audio. Nothing else. But they have a really useful place in learning. Why can’t I listen to key lessons, and reminders?
Or think about camera phones. Encouraging learners to collect media samples can be a rich and rewarding addition to their learning.But data push doesn't even get a look in on either of these examples. And most mobile web standards are irrelevant.
So where should we put our energy?
My personal philosophy on this is that we need to be able to do both. We should rejoice in the standards, and wherever possible support the emerging mobile web and data standards like XHTML, RSS, Wap, XML, CSS etc. But we also need to make the most of the unique features of specific devices. Just because the web browser on my smart phone doesn’t talk to my camera, does that mean I shouldn’t take a picture as part of my learning? Of course not! But I can guarantee that if all the learning is too standards or even browser centric this will be neglected.
So - I go for both. Some materials can be pushed out to multiple devices. But beware of losing the (possibly even richer) learning that happens with device specific features.