Re: [wsbpel-reqts] stv with quota

[Jeff Mischkinsky <jeff.mischkinsky@oracle.com>]

or just use the program which has a nice gui and gives you the winner.
     jeff
On Sep 15, 2004, at 2:19 AM, Furniss, Peter wrote:

> I promised/threatend/joked on Monday's call that I'd send a summary of 
> the full glory of single transferable vote with quota to this group.
>  
> This is useful where it is desirable/necessary to have multiple 
> selections with various sub-groups represented. So Northern Ireland, 
> student unions, and the sandwiches for a family picnic are suitable. 
> It's very easy to deal with for the voter, rather complicated for the 
> returning officer.
>   
> It predefined how many representatives (or packets of sandwiches) are 
> being chosen. (let this be R)
>  
> There are no restrictions on how many candidates there are, or how 
> many from a party (in fact one of the virtues of this system is that 
> "party" does not need to be defined in the system)
>  
> All voters assign preferences to as many candidates as they wish 
> (usually by putting numbers against the name, 1= first choice, but 
> small children could arrange the filling pots in order)   Voters do 
> not need to assign preferences to all candidates, but they must make 
> them unambiguous (a voter can't say several are equal rank), but 
> getting a later preference wrong does not invalidate an earlier one 
> (so ham=1, honey=2, cheese=3, peanut butter =3 , salmon=5) has valid 
> first and second preferences, but no valid 3rd or beyond)  [writing 
> this paragraph I found one should avoid the word "rank" - is rank 2 
> higher or lower than rank 1 ?]
>  
> Once the votes are in, they (or strictly those with a valid first 
> preference) are counted.(let this be V)
>  
> Now we establish the quota, which is V/(R+1). Let this be Q
>  
> All votes are sorted by first preference.
>  
> A:
> If the candidate with the highest value of votes is now over the 
> quota, they are declared elected.
>     If there are now R elected representatives, end the procedure.
>     If there are not yet R elected, compare the votes of the 
> just-elected candidate (let this be E) are compared to the quota Q.
>     If E == Q, discard all these votes, and go to A:
>     If E > Q, reduce these votes value to  (E-Q)/E of their current 
> value, and reallocate to next preference; go to A
>  
> If no candidate is over quota, take the votes of the candidate with 
> the lowest value of votes and reallocate according to next preference; 
> go to A
>  
> ----
> The procedure is usually described as assigning an initial value of 
> 100 to the votes, so quota is 100 *V /(R+1), and the value rounds down 
> to a whole number, but in concept you can work it with floating point 
> and an initial value of 1.0.
>  
> The case where R=1 (which is what we've just had for the ws-bpel name) 
> is a degenerate form of this, as the procedure terminates as soon as 
> someone is elected and the reallocation of a successful candidates 
> votes never happens.  But in other cases, that's the neat bit, because 
> it means a popular party doesn't use up all its strength on their best 
> candidate.
>  
> Actually, the sandwich example would have to treat the fillings as 
> parties, with "ham A", "ham B" etc.
>  
>  
>  
> Peter
>  
> ------------------------------------------
> Peter Furniss
> Chief Scientist, Choreology Ltd
> web: http://www.choreology.com
> email: peter.furniss@choreology.com
> phone: +44 870 739 0066
> mobile: +44 7951 536168
>  
>
--
Jeff Mischkinsky					jeff.mischkinsky@oracle.com
Director, Web Services Standards		+1(650)506-1975
Consulting Member Technical Staff	500 Oracle Parkway, M/S 4OP9
Oracle Corporation					Redwood Shores, CA 94065