Clearly knowledge creation (as opposed to information) through collaboration is a strong feature. As is display of ideas/percpetions/insights to a genuine audience- particularly in multi-media forms(non text based).

I am not sure what definitions of “creative” and “evaluative” is being used. Contributions can be innovative, artistic, created(in the sense of made).

Evaluation similarly might require more than simple judgement based upon prejudice, such as explicit criteria, values, shared principles of worthwhileness. Both have potential but are not guarnteed by social networking per se.

Similarly: Controversy the love of dissent “The rush of realisation that there is another view that may provoke personal enrichment and realignment.” May well be delightful for some but in my experience they are a rare breed. Handling this in social networking is a tricky thing. Where’s the incentive