Estimation Poker Face

Humans obey the Weber-Fechner law: we are good at distinguishing relative differences (this rock is twice as heavy as that one) but bad at absolute measurement (this rock weighs 4.2kg).

Story Points utilize this strength. By comparing a new task to a reference task (e.g., "Is this bigger or smaller than the Login page?"), teams can estimate complexity with much higher accuracy than predicting hours.

The "Cone of Uncertainty" shows that estimates at the beginning of a project can be off by 400%. Relative sizing helps teams focus on effort rather than false precision.