Using actuals with estimates - an experiment
I work with a group that's been estimating in pair hours for a while. We'll describe a story, everybody will write their estimate on a card, somebody collects the estimates, and we make an overall estimate. (The tricky part is that an estimate needs to include the tasks that aren't yet known but that will be discovered.)
We also track actuals. Whenever it's convenient, but definitely at the end of each day, the pair adds its tick marks onto the board.
We've used a couple approaches to coming up with "the" estimate. One was to have the longest-standing team member propose a consensus number => not consistently right. Then we tried taking the maximum estimate => usually too high.
Now, we're keeping track of who made what estimate. We compare estimates to actuals and decide who was the "winner" - the one with the most accurate estimates that week. When it's time to do new estimates, we let that person hear all the estimates, and they make the overall estimate we record.
It's too early to say how well this works. The same winner showed up twice in the first month, which may be an early indicator.
My estimates? I'm almost always too optimistic. So I'm going to pay more attention to how the winner thinks about our tasks.