As is so often the case, it was the diagram that attracted me to this article. Here it is full size. The bulk of the article is a list of the most important discoveries about digital collaboration. They apply equally to online learning. For example: "Whenever we have removed the barriers to connecting and collaborating between people, much more value has been created." The largest problem has always been the barriers to access (and in my opinion most talk in ed tech circles about design and pedagogy and the rest is just a way of avoiding this key issue). Also for example: "Asynchronous collaboration at scale is the richest and most powerful model for working together that we know." It's also an excellent way to support learning online. Via Mike Taylor.