I think michaelochurch's comment http://news.ycombinator.com/item?id=3522910 is more accurate than the article, but I think the type of problem does have quite a lot to do with it.
If the problem domain is defined by physics or physical function, I think most time estimates are going to be a lot closer. You might still get outliers, but most experienced people in the domain will probably give you decent estimates.
When you get human's preferences, design, business processes, and regulations into the mix, estimates can be wildly off. I once thought a defined business process would yield a decent software specification, but that never seemed to work out since the "flexibility" argument seems to creep in. Never mind multi-national companies that have a defined business process that is actually executed totally differently at every location.
If the problem domain is defined by physics or physical function, I think most time estimates are going to be a lot closer. You might still get outliers, but most experienced people in the domain will probably give you decent estimates.
When you get human's preferences, design, business processes, and regulations into the mix, estimates can be wildly off. I once thought a defined business process would yield a decent software specification, but that never seemed to work out since the "flexibility" argument seems to creep in. Never mind multi-national companies that have a defined business process that is actually executed totally differently at every location.