I think that small error inside a value description could result in bad result, but it is not so, if we have a list of independent values.

In phone example if I lose one digit from someone number, I will not get 90 per cent of him, but if I lose 1 phone number from my phone book, it will be 90 per cent intact.

Humans tend to have many somewhat independent values, like some may like fishing, snorkeling, girls, clouds, etc. If he lost one of them it is not a big deal, it is almost him and it happens all the time with real humans, as their predispositions could change overnight.