Medium , from the same minds that brought us Twitter, is already a new kind of online publishing platform...and now it's trying out a novel commenting system for published pieces: direct-feedback "notes" for the author.
An email to early beta-phase testers today describes the noting process as being as easy as moving your cursor over the text you'd like to comment on, clicking on a little "+" icon, and typing in your feedback. The trick is that only you and the author of the piece get to see your comment at first. On receipt of an email concerning the comment, the author can reply, or permanently "hide" the note, or choose to make it public--whereafter anyone else can comment on the note, too.
The trick here is that comment moderation is directly under the author's control, so it's not an open, free-for-all system in the way that commenting systems on many online publications tend to be. Managing  open commenting systems to prevent trolling or otherwise abusive  commenting  has been a perennial problem for many sites. Medium  seems to be keen to avoid this controversy right from the start.
[Image: Flickr user cowbite ]