A paperless class completely changes the role of the teacher. I become a participant in the learning. I become the guide instead of the sage on the stage. Instead of handing out the knowledge via lecture, students gain knowledge by researching it. Just as important, they gain knowledge by back and forth discussion with others in the class. In many ways, this is exactly what we do in the PLS classroom. Using sources online such as articles, parts of textbooks, blogs by experts, and information from each other we gain knowledge on a topic. According to our textbook, one of the big shifts is that students no longer need mastery (necessarily) of the material but they do need mastery of how to find the information.
Measuring learning in a paperless class would be a challenge. Of course, you can measure knowledge based on any papers, blogs, presentations (which would include pictures, videos, and possible music) to gage the learning that took place. You could also measure growth based on the responses to discussions and responses taking place within the class.
Building a learning network in a paperless class would actually be easier once students understood how to create that network. They would need to be taught about social bookmarking sites such as Diigo.com, blogging sites such edublogs.org, as well as tags and the best way to use them so that their work could be found outside the class. They also need to become familiar with publishing tools! Once they have a basic knowledge of these tools, building the network is easy!