[EM] IRV proponents figure out how to make IRV precinct-summable

[Raph Frank]

On Wed, Mar 25, 2009 at 7:19 AM, Juho Laatu <juho4880 at yahoo.co.uk> wrote:
> 4) To hide the individual votes for
> privacy and security reasons. Published
> ranked votes open up some doors for vote
> buying and coercion. It is quite easy to
> generate unique votes when the number of
> candidates increases. (Also individual
> ballots are interesting from point 1, 2
> and 3 point of view, but dangerous.)

One option here would be to restrict the number of rankings.  If the
number of voters is higher than Candidates ^ Rankings, then most
possible configurations are likely to receive at least 1 'hit'.

Another option would be to do it based on the ballot data.  For example

1) Start with 1 "pile" of all the ballots
2) Split all piles into sub-piles based on highest ranked difference
3) For each group of sub-piles (from same pile), combine the smallest
sub-piles together until the smallest has at least N N (say 10)
ballots,
4) Declare all sub-piles as piles and return to 2), unless no change
was made in 3)

So, if the ballots were

30) A>B>C
20) C>A>D
13) C>B>D
1) A>B>C>X>Y>Z

The process would be:

Pass 1
Pile A>
30) A>B>C
1) A>B>C>X>Y>Z

Pile C>
20) C>A>D
13) C>B>D

Pass 2:
Pile A>B
30) A>B>C
1) A>B>C>X>Y>Z

Pile C>A
20) C>A>D

Pile C>B
13) C>B>D

Pass 3:
Pile A>B>C
30) A>B>C
1) A>B>C>X>Y>Z

Pile C>A>D
20) C>A>D

Pile C>B>D
13) C>B>D

Pass 3:
Sub-Pile A>B>C
30) A>B>C

Sub-Pile A>B>C>X
1) A>B>C>X>Y>Z

Pile C>A>D
20) C>A>D

Pile C>B>D
13) C>B>D

Sub-pile A>B>C>X hasn't enough ballots, so is combined with the next
lowest sub-pile, A>B>C

Pile A>B>C
30) A>B>C
1) A>B>C>X>Y>Z

Pile C>A>D
20) C>A>D

Pile C>B>D
13) C>B>D

No change has occured, so end.

The results would be declared as

31) A>B>C
20) C>A>D
13) C>B>D

This gives a loss of accuracy, but hopefully not to much.

Also, it doesn't work if you are providing ballot images.

> In summary, maybe raw digitized ballots
> are good enough in most cases for the
> computers, but humans may need more
> compact information (not necessarily
> summable) for various reasons.

The theory was that the ballots would be published and
non-profit/bored programmers could convert them into rankings.

The government would publish a block of ballots and their associated
official rankings.

If there was errors, it would be possible for them to provide a series
of links to offical ballot/rankings pairs which clearly don't match
what is actually on the image.

> The
> privacy point may set requirements on
> what to publish and what not (some
> countries are already now quite strict
> on this).

You could have a rule that a ballot is only valid if it doesn't have
marks.  Also, ballots images could have parts of the image censored,
to cover up those marks.  Ofc, the actual boxes where the person
indicates the rankings would have to be shown.

This somewhat goes against the principle of multiple independent
groups imaging the ballots for comparison to the official list.  In
principle, you could require that they mask off all parts of the image
other than the ranking boxes and the ballot ID number.

I guess it depends on the lengths people would go to.  In principle,
you could require that the seller use a special font when filling in
their ballot.