[davismwfl]

I wouldn't think too many as the arrow is pointing up and not down as it would be for expanded comments. In addition, it exists on every question/answer regardless if there are responses.

But I see your point that the context is subtle and maybe some people would miss it and still click.

Just my opinion too, but HN is a uber simplistic interface that isn't following a lot of current trends, but it also isn't really designed for the consumer level user either.

[kappaloris]

>I wouldn't think too many as the arrow is pointing up and not down as it would be for expanded comments.

People might think the arrow doesn't indicate the comment thread state ('expanded') but the action that will be performed when clicked ('collapse'), which might also inlude the top-post (that would be consistent with the 0-replies case).

[davismwfl]

Fair point, didn't think of it that way.