Terry Anderson drew my attention today to the concept of the 'affinity space' from James Paul Gee (always an interesting writer), which bears a marked resemblance to our understanding of the set as a social form for learning, and with which I was previously unfamiliar. This is certainly something I need to investigate further. At first reading I think the affinity space is a (large and probably the most important) subset of what we mean by a 'set' - it is concerned with people sharing an interest and a normally virtual space but otherwise having no social connection to speak of, which is exactly how we distinguish set from net social forms.  It is also a close cousin of communities of interest and interest (or interest-based) networking, that are very much in the same area but that gained their names from people with perspectives slanted by where they already had expertise and experience. I like the term 'affinity space' far better than those terms for the reasons mentioned in the Wikipedia article, which are very similar to the reasons we went for the term 'set'.

Our concept of the set additionally recognizes learning value in sets that are not directly or only concerned with the kinds of affinity mentioned in the article - e.g. those of people of similar, greater or lesser abilities, those of people simply near to one another, those where personal attributes like culture are significant - which becomes more significant when thinking about how collectives emerge or are formed from sets. Also, we are keen to emphasize the continuous fuzzy boundaries between sets and groups (e.g. tribes, religions, Goths) and between sets and networks (e.g. circles of friends, college alumni), seeing most such collections of people as occupying blended or overlapping social forms. But this is a useful concept that I suspect we will use in future to characterize one of the purest forms of set used for learning purposes and one that has most relevance in an online context. Whatever the minor distinctions, and whether the concepts turn out to be almost the same or just similar, I am glad to know that others, especially those with the intellectual muscle and creativity of Gee, think it is an idea whose time is well upon us.