zlacker

>>mattjh+(OP)
Is it going to take more than two hours?

Is it going to take more than two days?

Is it going to take more than two weeks?

Is it going to take more than two months?

Is it going to take more than two years?

If you can answer these questions, you can estimate using a confidence interval.

If the estimate is too wide, break it down into smaller chunks, and re-estimate.

If you can't break it down further, decide whether it's worth spending time to gather information needed to narrow the estimate or break it down. If not, scrap the project.

>>xn+VB
There’s also something more concrete about asking “Can you get it done by end of tomorrow? What does that require?”

I prefer it over estimating which feels more like asking the length of a piece of string.

>>scott_+wo1
The problem I have is, conceptually a task always looks easy, but then as your coding, you hit several problems that are not simple to overcome - in fact, lot of times these issues turn into almost insolvable problems that blow out any time estimates ;(

>>alfied+NX1
This why you should use confidence intervals for estimates. Use a 80% confidence interval, for example. 10% of the time, you should come in under the best case estimate. 10% of the time, it should take longer than the worst case estimate.

How do you know if your estimate is good? Would you rather bet on your estimate or on hitting one of 8 numbers on a 10-number roulette wheel? If you prefer one of the bets, adjust your estimates. If you're indifferent between the bets, the estimates accurately reflect your beliefs.

(The roulette wheel is from the book, How to Measure Anything by Hubbard. Confidence interval estimates are from LiquidPlanner, https://web.archive.org/web/20120508001704/http://www.liquid...)