

Oscar best picture changed from single vote to full preferential ranking - huangm
http://carpetbagger.blogs.nytimes.com/2009/12/09/oscars-new-math/

======
Maro
When reading about voting systems, I'm always reminded of Arrow's
impossibility theorem, which everybody should be aware of:

<http://en.wikipedia.org/wiki/Arrow%27s_impossibility_theorem>

In short, no "fair" voting system can satisfy these three criteria:

\- If every voter prefers X over Y, then the group prefers X over Y.

\- If every voter prefers X over Y, then adding Z to the slate won't change
the group's preference of X over Y.

\- There is no dictator.

~~~
Eliezer
That can't be correct as written because if I could magically extract
everyone's scalar utility function from their minds, a mixture of utility
functions would satisfy those three criteria.

You need an additional requirement, "The citizen's true ordering of
preferences is the only data presented to the algorithm." In other words the
algorithm can't access the scalar utility function, only the ordering, and
every similar ordering has to result in the same social ordering - no mixture
of utility functions will satisfy this, obviously. If you want to prevent
"strategic voting" that would impose other requirements as well.

Impossibility theorems often aren't as impossible as they look, and indeed
Arrow's Impossibility Theorem makes a good illustration of _that_ , especially
as the evasive answer is pretty obvious if you walk around thinking of
expected utility maximizers all day long. Doesn't work for non-mind-reading
applications because of the strategic voting problem, but in terms of whether
it's _possible_ for a society to aggregate the true utilities of its citizens,
no sweat.

~~~
lmkg
If you could magically extract everyone's scalar utility function, then it
wouldn't be a voting system.

The requirement that you state is in the definition. It's just implicit in the
word "voting" rather than explicitly stated. Arrow's Theorem does rely on an
explicit definition of voting, which is that voters make discrete choices
about their candidates subject to certain criteria. Some theorem (possibly
part of Arrow's Theorem) says that it's not possible to eliminate the
potential for strategic voting in a 3+ party system without negating other
desirable qualities like those listed above.

------
amalcon
Looks like they're using instant runoff voting:
<http://en.wikipedia.org/wiki/Instant_runoff_voting>

~~~
nas
Boo. IRV sucks (probably as much or more than plurality). Approval voting FTW.
See <http://zesty.ca/voting/sim/>. Noice how Approval and Condorcet voting
produce the same pictures (aside from Approval having a little fuzzier edges).

~~~
bradbeattie
Boo. Approval sucks. Schulze method for the long haul. Majority criterion is
fairly important, yeah? Approval (aka restricted range voting) fails that.

On a side note, I've been working on a JSON web service to calculate election
winners in various systems. Feedback would be sweet.
<http://vote.cognitivesandbox.com>

~~~
nas
IMHO, Schulze is too complicated for the average voter. People need to
understand the voting system. I don't deny that it's theoretically better.

~~~
lmkg
I heartily disagree that people need to understand the voting system. Ideally,
people should just be thinking about ranking the candidates. If the way that
the votes are counted will affect the way they vote, that means that strategic
voting is a prominent part of the system.

Granted, strategic voting is theoretically unavoidable without introducing
other degeneracies. But on a quantitative scale, its effect and its frequency
are smaller under some voting systems than others.

~~~
bradbeattie
<http://en.wikipedia.org/wiki/Arrows_impossibility_theorem>
<http://en.wikipedia.org/wiki/Gibbard–Satterthwaite_theorem>

------
hugh_
The important question is: how likely is this to change the results? In recent
decades there's been a trend for the Best Picture Oscar to wind up going to
films which may not be all that good but which are seen as "Oscar-worthy" due
to weighty subject matter or otherwise "seeming smart". Historical dramas have
made up something like twenty out of the last thirty years' winners, including
such so-so films as Braveheart. No comedy has won since Shakespeare in Love
(which was acceptably smart-seeming because it had Shakespeare in it) and
before that it was Annie Hall (which, incidentally, beat Star Wars).

I wonder if preferential ranking will improve the quality of winners by better
reflecting the true preferences of the voters rather than the preferences the
voters seem to think they ought to have.

------
qjz
I wonder how long this will last. "Fair" voting approaches such as
preferential ranking attempt to address the challenge of producing an outcome
that is agreeable to everyone, which is subtly different than recognizing the
"best". This will favor a compromise result over one that is challenging,
thought-provoking, or "artistic" in other meaningful ways.

~~~
hugh_
What kind of voting system would result in correctly recognizing "the best" in
your opinion? And how does "the best" film differ from the compromise
candidate?

~~~
qjz
In my opinion, the "best" work also scores highly across the criteria. In my
experience, the voting body increasingly ignores criteria as it gets larger.
Perhaps the quality of the results would improve if the voting body had to
rank the criteria to provide weights, then rank their preferences for each
criteria. This informs the voting body and the results might surprise (and
even please) everyone. But that's complicated.

Having designed and run preferential ranking systems for selecting multiple
winners (unlike the Oscars), I've seen that polarizing choices tend to get
eliminated regardless of artistic merit. Sometimes, we address this by letting
the results of the larger voting body inform the decision of a smaller panel,
who are allowed to vary the algorithm and play with other variables before
making the final determination (in ranking subjective things like art,
fairness in voting is not always the main priority).

The problem with the compromise candidate is that it is often not anyone's
first preference, therefore nobody considers it the best. This is especially
true when the number of candidates is large.

As an experiment, I'd like to ask voters to select only the best and worst
single candidates, then apply a straightforward preferential ranking algorithm
against those as if they were the top two choices. I wouldn't be surprised if
this would narrow the field to works with the most artistic merit.

------
finin
I've been convinced that range voting it the best -- better than IRV and
approval voting. It's intuitive also. See
<http://en.wikipedia.org/wiki/Range_voting>

~~~
bradbeattie
Range voting is one of the few systems that requires strategic voting with
only two candidates. This isn't a good thing. :/

    
    
      Demographic A (10 voters): Candidate X valued at 40, Y at 60
      Demographic B (3 voters): Candidate X valued at 100, Y at 0
    
      Candidate X gets 700 points
      Candidate Y gets 600 points
    

This scenario demonstrates how susceptible range voting is to tactical voting.

------
rokhayakebe
I always wondered what HN would look like if we used preferential ranking, and
almost started to work on something earlier this month.

~~~
byrneseyeview
How does that work when we get different stories at different times? You might
be able to come up with a system in which everyone votes on the day's top
stories, and then they're ranked, but that would be tedious and would not
clearly produce a better result than what we have now.

~~~
gojomo
Not saying any of this is necessarily a good idea, but to explore an
interesting vein of ideas:

What if the front page weren't continuously updated, but only updated after
fixed balloting periods (say, 6-12 hours long)? Voting would only happen when
_all_ stories for a period were in. Each voter would see a different
randomized order-of-presentation.

Yes, it'd completely change the character of the site. No immediate upvote
feedback for being first to submit a 'hot' story. Stories would be guaranteed
to lag other 'breaking' news sites by some number of hours.

But these changes might be good things: reducing both the incentive to submit,
and the rewards for constant reading, of frothy/gossipy linkbait.

A site seeking impressions over all else wouldn't want this approach -- but HN
isn't ad-driven. 'Slow HN' might be a better HN.

