Allow user to submit feedback on a per-article basis, which goes to (admins?) for review/improvement/etc. We have a use case, as privacy is key and publicly visible comments would be a powder-keg. (bad mouthing company, conversations between users, unrelated info, moderation needed, good/bad advice, cluttering, wasting user's time reading comments, talking about other products THEY have access to but other's don't, etc.)
This could be combined with a thumbs up/thumbs down rating system, where thumbs up is accepted and thumbs down is accepted, but also prompts for (optional) written feedback.