I am researching interactions on mobile devices and for that purpose I am trying to compile a list of mobile device categories. The classification I have so far consists of 4 main categories:
The problem with this categorization is that it is not clear, where to include such devices as the iPod Touch and other iPods, the Kindle, smartphones which are larger than 4 inches, etc. One possible option would be use the classification provided by Mark Weiser with his pads, tabs and boards, yet I feel that this is also somewhat limiting and does not reflect the plethora of mobile devices we have today.
I was also looking for existing classifications done by other researchers, but unfortunately I was not able to find anything suitable so far. I was hoping that you could suggest something and maybe point me to some relevant articles on the topic.