Subject: [EAI] Please - Don't state preferences yet!

From: Harald Tveit Alvestrand <[email-masked]>
Date: Mon, 23 Jul 2007 09:23:36 -0500

Note - my message was intended to start the discussion on the subject on 
how to decide on a MIME type. I am NOT recording people's position until 
we've decided what mechanism to use to decide!

This is an agenda item for Chicago.

                 Harald

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---

From: "Charles Lindsey" <[email-masked]>
Date: Tue, 24 Jul 2007 12:34:49 +0100

> we've decided what mechanism to use to decide!

Ah! The methods you have proposed is known as "Alternative Vote", or "AV".  
It usually works fine, but can sometimes go completely wrong. For example,  
in the Lilliput Referendum to decide on which end an egg should be opened,  
the alternatives were:

Big-Endian
Little-Endian
Scrambled-egg

Naturally, the Big-Endians all voted for Big first and Little last, with  
Scrambled in the middle. The Little-Endians all votes for Little first and  
Big last, with Scrambled in the middle.

Only 1 person actually put Scranbled first, and hence it got eliminated  
 from the count, leaving a dead heat between Big and Little. Whereas in  
fact, if Scrambled has won, everybody would have been reasonably happy  
(their real desire was to ensure that the other main party failed, rather  
than that their own succeeded). Hence the compromise got squeezed out.

The ideal mathod, designed by the Marquis de Condorcet, copes better with  
such situations, since it examines the complete matrix of how many people  
prefer each possible option over each of the others.

So with 50 people voting 1. Big, 2. Scrambled, 3. Little
and 50 people voting     1. Little, 2. Scrambled, 3. Big
and 1 person voting      1. Scrambled 2. [don't care between B and L]

you get the matrix

    B  S  L
B  - 50 50
S  50 - 50
L  51 51 -

And Scrambled wins because it was preferred over Big by 51:50
and it was preferred ov Little by 51:50.

The Condorcet can result in a tie (but so can AV). And it can also result  
in a cycle (but very rarely does, and when it does it indicates a totally  
confused electorate).

I have a program, written in C, that will work it all out, which I can  
supply on request. For example, on the group of people who have voted so  
far (which is not terribly meaningful, given that lots more people have  
not yet voted at all), my program would give:

K:  
message/intl-email--------------------------------------------------------+
J:  
message/ima------------------------------------------------------------+  |
I: message/utf8-email--------------------------------------------------+   
|  |
H: message/utf8eai--------------------------------------------------+  |   
|  |
G: message/eai---------------------------------------------------+  |  |   
|  |
F: message/i18n-email-----------------------------------------+  |  |  |   
|  |
E: message/mail--------------------------------------------+  |  |  |  |   
|  |
D: message/global---------------------------------------+  |  |  |  |  |   
|  |
C: message/international-----------------------------+  |  |  |  |  |  |   
|  |
B: message/i18n-----------------------------------+  |  |  |  |  |  |  |   
|  |
A: message/utf8smtp----------------------------+  |  |  |  |  |  |  |  |   
|  |
                                                |  |  |  |  |  |  |  |  |   
|  |
Klensin                                        -  -  2  3  1  -  -  -  -   
-  4
Lindsey                                        4  5  6  7  8  1 10  9  3  
11  2
Newman                                         -  7  1  2  4  6  9  8  5  
10  3
Zoltan                                         5  8  1  7  6  4 10 11  3   
9  2

RESULT:

C: message/international is preferred to A: message/utf8smtp      by 3 : 1
C: message/international is preferred to B: message/i18n          by 3 : 1
C: message/international is preferred to D: message/global        by 4 : 0
C: message/international is preferred to E: message/mail          by 3 : 1
C: message/international is preferred to F: message/i18n-email    by 3 : 1
C: message/international is preferred to G: message/eai           by 4 : 0
C: message/international is preferred to H: message/utf8eai       by 4 : 0
C: message/international is preferred to I: message/utf8-email    by 3 : 1
C: message/international is preferred to J: message/ima           by 4 : 0
C: message/international is preferred to K: message/intl-email    by 3 : 1

C: message/international is therefore a condorcet winner

The following matrix shows the votes in more detail.
The number at [row,column] indicates the number of voters who placed the
[row] option ahead of the [column] option in their order of preference

K: message/intl-email--------------------------------------------------+
| J: message/ima----------------------------------------------------+  |
| | I: message/utf8-email----------------------------------------+  |  |
| | | H: message/utf8eai--------------------------------------+  |  |  |
| | | | G: message/eai-------------------------------------+  |  |  |  |
| | | | | F: message/i18n-email-------------------------+  |  |  |  |  |
| | | | | | E: message/mail--------------------------+  |  |  |  |  |  |
| | | | | | | D: message/global-------------------+  |  |  |  |  |  |  |
| | | | | | | | C: message/international-------+  |  |  |  |  |  |  |  |
| | | | | | | | | B: message/i18n-----------+  |  |  |  |  |  |  |  |  |
| | | | | | | | | | A: message/utf8smtp--+  |  |  |  |  |  |  |  |  |  |
| | | | | | | | | | +-----------------  \\  2  1  2  2  0  2  2  0  2  0
| | | | | | | | | +-------------------   1 \\  1  1  1  0  3  3  0  3  0
| | | | | | | | +---------------------   3  3 \\  4  3  3  4  4  3  4  3
| | | | | | | +-----------------------   2  3  0 \\  2  2  4  4  2  4  2
| | | | | | +-------------------------   2  3  1  2 \\  2  4  4  2  4  1
| | | | | +---------------------------   3  3  1  2  2 \\  3  3  1  3  1
| | | | +-----------------------------   1  0  0  0  0  0 \\  1  0  2  0
| | | +-------------------------------   1  0  0  0  0  0  2 \\  0  2  0
| | +---------------------------------   3  3  1  2  2  2  3  3 \\  3  0
| +-----------------------------------   1  0  0  0  0  0  1  1  0 \\  0
+-------------------------------------   4  4  1  2  3  3  4  4  4  4 \\

The second matrix shows the effect of subtracting [column,row] from
[row.column] so as to give the majority in favour of [row] as against  
[column].
Observe that the winning row(s) has no negative entries.

K: message/intl-email--------------------------------------------------+
| J: message/ima----------------------------------------------------+  |
| | I: message/utf8-email----------------------------------------+  |  |
| | | H: message/utf8eai--------------------------------------+  |  |  |
| | | | G: message/eai-------------------------------------+  |  |  |  |
| | | | | F: message/i18n-email-------------------------+  |  |  |  |  |
| | | | | | E: message/mail--------------------------+  |  |  |  |  |  |
| | | | | | | D: message/global-------------------+  |  |  |  |  |  |  |
| | | | | | | | C: message/international-------+  |  |  |  |  |  |  |  |
| | | | | | | | | B: message/i18n-----------+  |  |  |  |  |  |  |  |  |
| | | | | | | | | | A: message/utf8smtp--+  |  |  |  |  |  |  |  |  |  |
| | | | | | | | | | +-----------------  \\  1 -2  0  0 -3  1  1 -3  1 -4
| | | | | | | | | +-------------------  -1 \\ -2 -2 -2 -3  3  3 -3  3 -4
| | | | | | | | +---------------------   2  2 \\  4  2  2  4  4  2  4  2  
winner
| | | | | | | +-----------------------   0  2 -4 \\  0  0  4  4  0  4  0
| | | | | | +-------------------------   0  2 -2  0 \\  0  4  4  0  4 -2
| | | | | +---------------------------   3  3 -2  0  0 \\  3  3 -1  3 -2
| | | | +-----------------------------  -1 -3 -4 -4 -4 -3 \\ -1 -3  1 -4
| | | +-------------------------------  -1 -3 -4 -4 -4 -3  1 \\ -3  1 -4
| | +---------------------------------   3  3 -2  0  0  1  3  3 \\  3 -4
| +-----------------------------------  -1 -3 -4 -4 -4 -3 -1 -1 -3 \\ -4
+-------------------------------------   4  4 -2  0  2  2  4  4  4  4 \\

-- 
Charles H. Lindsey ---------At Home, doing my own thing------------------------
Tel: +44 161 436 6131                       
   Web: http://www.cs.man.ac.uk/~chl
Email: [email-masked]      Snail: 5 Clerewood Ave, CHEADLE, SK8 3JU, U.K.
PGP: 2C15F1A9      Fingerprint: 73 6D C2 51 93 A0 01 E7 65 E8 64 7E 14 A4 AB A5

---

From: Harald Tveit Alvestrand <[email-masked]>
Date: Tue, 24 Jul 2007 07:34:11 -0500

--On 24. juli 2007 12:34 +0100 Charles Lindsey <[email-masked]> wrote:

>>  how to decide on a MIME type. I am NOT recording people's position
>> until   we've decided what mechanism to use to decide!
>
> Ah! The methods you have proposed is known as "Alternative Vote", or
> "AV". It usually works fine, but can sometimes go completely wrong.
.....

> prefer each possible option over each of the others.

Thanks for the pointer - <http://en.wikipedia.org/wiki/Condorcet_method> 
gives more detail of Concordet voting mechanisms.

                  Harald

---

From: John C Klensin <[email-masked]>
Date: Wed, 25 Jul 2007 04:20:26 -0400

--On Tuesday, 24 July, 2007 07:34 -0500 Harald Tveit Alvestrand
<[email-masked]> wrote:

>>> Note - my message was intended to start the discussion on
>>> the subject on how to decide on a MIME type. I am NOT
>>>  recording people's position until   we've decided what
>>> mechanism to use to decide!
>> 
>> Ah! The methods you have proposed is known as "Alternative
>> Vote", or "AV". It usually works fine, but can sometimes go
>> completely wrong.
> .....
> 
>> 
>> The ideal mathod, designed by the Marquis de Condorcet, copes
>> better with such situations, since it examines the complete
>> matrix of how many people prefer each possible option over
>> each of the others.
> 
> Thanks for the pointer -
> <http://en.wikipedia.org/wiki/Condorcet_method> gives more
> detail of Concordet voting mechanisms.

Since I used to do election analysis for a living, long ago, the
reality is that any of these methods can produce results that
are inconsistent with the desires/ intent of those responding,
and differ largely by the assumptions one makes about the intent
one wants to optimize.

Alternate vote optimizes first choices; while there are edge
cases (including possibilities for ties) something basically has
to be someone's first choice in order to win.

Condorcet optimizes one particular preference model.  In
particular, as Charles's model illustrates very well, it assumes
that an option that is everyone's second choice is better than
any option that is the first choices of a minority of the
voters.  As such, one might think of it as one version of the
model that a good choice is the one that leaves everyone more or
less equally unhappy.

It is important to note that any of the systems, including the
ones discussed below, get a lot more complicated, with more ways
to get into strange cases, as the number of options rises above
three.   And any of them can be gamed by colluding voters,
although some are more easily gamed than others.

But there are many other options.   For example, in a situation
like the one we have, there is a strong argument that one should
first examine "I completely hate this" votes, eliminating any
options that are intensely disliked by a non-trivial number of
people, and only then applying a model based on affirmative
preferences to what is left.  Some feel that works better in
environments in which there is a lot of indifference (as long as
an answer is found) but a desire to eliminate really bad choices
before one is approved based on weak preferences.   This sort of
system is often considered bad for elections but good for some
other types of preference choices.

And then there are a whole series of "weight and scale"
techniques, some of them involving explicit elucidation of
strength of preferences and giving more weight to those who
care.  

Again, none of these is "right"; they just balance the factors
and considerations differently.

     john

---

From: Arnt Gulbrandsen <[email-masked]>
Date: Wed, 25 Jul 2007 10:58:39 +0200

John C Klensin writes:
> For example, in a situation like the one we have, there is a strong 
> argument that one should first examine "I completely hate this" 
> votes, eliminating any options that are intensely disliked by a 
> non-trivial number of people, and only then applying a model based on 
> affirmative preferences to what is left.

+1

But please name/suggest a method that has these properties and wasn't 
designed by a naïve layman.

Arnt

---

From: "Charles Lindsey" <[email-masked]>
Date: Thu, 26 Jul 2007 11:42:54 +0100

> although some are more easily gamed than others.

AFAIK, there is no known way of "gaming" the Condorcet system.
> other types of preference choices.

Yes, and that also relates to the "equally unhappy" idea, which is  
probably as good as you will ever get when there are extremely polarized  
opinions. Condorcet gets a little nearer to that than AV, but not entirely  
so.

The main benefit of Condorcet lies in resolving cases where there are a  
large number of similar cases (e.g. message/international vs message/intl)  
between which nobody really cares). And it works best when everybody is  
encouraged to give at least some preference value to _every_ option, even  
the ones they don't like.

We have used Condorcet for creation of Newsgroups in uk.* in cases where  
there have been disagreements over alternative names or alternative  
moderation options, and it seems to work well. Nobody understands quite  
how it works, but when the results are presented clearly, everyone can  
see, and accept, that it has reached a sensible conclusion (usually, it  
turns out the way people were expecting it to, and the mavericks who  
insisted on including the unpopular options on the ballot are easily seen  
to have attracted no support).

---

From: Arnt Gulbrandsen <[email-masked]>
Date: Thu, 26 Jul 2007 12:56:13 +0200

> AFAIK, there is no known way of "gaming" the Condorcet system.

IETF participants aren't exactly notorious for gaming WG decisions. The 
most important concern (IMO) is that people might spew flames over a 
result they dislike.

Arnt