Rainfall and Olympic pools - view on the website
We can't imagine scale. Our ability to estimate anything large, complicated, or opaque is poor.
Area is often referred to 'as the number of football fields,' and volume is 'the number of Olympic pools.' Do you know the area or volume of either? No. Me neither.
As a side note, in looking up the number of Olympic pools in Sydney harbour (238,000), I came across that 'Sydharb' is a unit of volume of water in Australia - 562 gigalitres.
Last year, I helped someone build a shed (7m by 12m). During the week, it drizzled on and off most days. Only when we had the roof up but not installed the gutter could you see the water running off the shed. In this brief construction period, it was apparent how much water was falling over a relatively small area.
If you'd asked me to estimate the volume of water coming off the roof based on the rain I’d seen all week, I would have been off by more than I could imagine. I've spent considerable time in the rain and am generally good at estimation.
Did it matter that I was wrong with my estimate? No. The water would be stored in a tank, and we didn’t need to do anything with this information.
Whatever you're estimating should matter more, and you're probably no better than I am.
Next time you're in a meeting, and someone says, 'I think it's about', remember that a poor guess is worse than no guess.
If you're going to bother guessing, spend the time and effort to come up with a reasonable approximation.
Andrew
Want more? Great.
On LinkedIn, I describe why this concept is hard to implement.
Here's a short data bite if you want to hear me expand on the idea.