[EM] Gervase Lam, ratings reply

[Adam Tarr]

Brian Olson wrote:

>Adam  Tarr wrote:
>
>>>Some rated systems behave differently if signed numbers are used or if
>>>positive-only numbers are used.
>>
>>when?
>
>Combinations of normalization and shifting can alter a vote such that you 
>can't reverse the process and get the original vote back again.
>
>Shift, then normalize, and if you try to shift back the vote will be 
>different.

OK, but if you shift and scale either one, you can make it look like the 
other.  Then all normalization will work out the same.

Sure, you can't use the exact same definition of how to evaluate the 
ballots, but that's not significant.  The ballots contain exactly the same 
information, and can be converted from one to the other and back again.

It's the process of normalization that loses information, not the process 
of shifting the scale.  There's no real difference between a -10->10 range 
and a 0->20 range, except the psychological one.

-Adam