How should a team handle disagreements about story-point estimates in Scrum?
During estimation, the Product Owner presents a user story that seems clear to a team that usually knows their strengths and weaknesses, and that is not hostile. What should the Scrum Master do if the story is judged very differently by the team members, but they can't convince each other enough to agree on a story-point estimate?For example, let's say two opinions arise. Some see this as a rather easy story (e.g. 2 points) and others foresee technical complications and judge that the story should be 20 points. The 2-point voters say, "I understand your opinion, but don't think those complications are valid." The 20-point voters say, "The past tells us that these things are always a lot more complicated then they seem."I assume that if the issue is not clarified the 20-point faction will not commit to the user story if it is (in their eyes) under-estimated.What should the Scrum Master do in this case? Go for the average? Choose the worst case? Or accept this user story as "high-risk" with only a semi-commitment during Sprint Planning?