> The moment that story estimating becomes time estimating...stop. That's not what it is there for and you're not trying to assign out every minute for a person. I don't see the distinction here. The whole reason you're estimating things is to guess at how long they'll take. If the story points do not translate to time, what use are they?
is the task description ambiguous? then estimates will be all over the place, so you'll know you need to spend more time on specifying the task.
and risk minimalization. if the estimated complexity is above some threshold, you need to break down the task.
to get a time estimate you use the historic burn down rate (average story points per sprint completed/delivered)
but it's not something you can do up front.