Asp Forum - Unofficial Ruby Quiz -- Ranking Choices

Ken Bloom

5/3/2007 11:49:00 PM

Apparently some people around here can't stand Ruby Quiz withdrawal. For
those people, here's a quiz question I just came up with.

I have a list of some items, and I would like to manually rank which ones
are most important to me. But it's not easy to rank them when I'm looking
at them all at once, so I'd like to consider them in pairs and choose
from each pair which one is most important to me. Then I'd like to use my
answers to those questions to create a ranked list. Anyone think they can
come up with a good program to quiz me about these items pairwise, and
output a ranking?

Extra credit: come up with a solution that lets me take the quiz multiple
times, and outputs a single ranked list reflecting all of my sessions
taking the quiz.

I have my solution to the basic question, but I want to see what other
people come up with.

--Ken

--
Ken Bloom. PhD candidate. Linguistic Cognition Laboratory.
Department of Computer Science. Illinois Institute of Technology.
http://www.iit.edu...

6 Answers

Bill Guindon

5/4/2007 12:42:00 AM

On 5/3/07, Ken Bloom <kbloom@gmail.com> wrote:
> Apparently some people around here can't stand Ruby Quiz withdrawal. For
> those people, here's a quiz question I just came up with.
>
> I have a list of some items, and I would like to manually rank which ones
> are most important to me. But it's not easy to rank them when I'm looking
> at them all at once, so I'd like to consider them in pairs and choose
> from each pair which one is most important to me. Then I'd like to use my
> answers to those questions to create a ranked list. Anyone think they can
> come up with a good program to quiz me about these items pairwise, and
> output a ranking?

Thanks much for filling in. I'm very interested, and I hope I have
the time to take a shot at this one.

Could you elaborate on the rules a bit? Do all possible pairs have to
be evaluated, or should it deduce values based on previous answers?

banana is more important than apple
orange is more important than banana
no need to compare apples to oranges (pardon the pun).

> Extra credit: come up with a solution that lets me take the quiz multiple
> times, and outputs a single ranked list reflecting all of my sessions
> taking the quiz.
>
> I have my solution to the basic question, but I want to see what other
> people come up with.
>
> --Ken
>
> --
> Ken Bloom. PhD candidate. Linguistic Cognition Laboratory.
> Department of Computer Science. Illinois Institute of Technology.
> http://www.iit.edu...

PS: typo on your home page: 'contected', looks bad for a linguistics major ;)

--
Bill Guindon (aka aGorilla)
The best answer to most questions is "it depends".

Chris Carter

5/4/2007 3:14:00 AM

On 5/3/07, Ken Bloom <kbloom@gmail.com> wrote:
> Apparently some people around here can't stand Ruby Quiz withdrawal. For
> those people, here's a quiz question I just came up with.
>
> I have a list of some items, and I would like to manually rank which ones
> are most important to me. But it's not easy to rank them when I'm looking
> at them all at once, so I'd like to consider them in pairs and choose
> from each pair which one is most important to me. Then I'd like to use my
> answers to those questions to create a ranked list. Anyone think they can
> come up with a good program to quiz me about these items pairwise, and
> output a ranking?
>
> Extra credit: come up with a solution that lets me take the quiz multiple
> times, and outputs a single ranked list reflecting all of my sessions
> taking the quiz.
>
> I have my solution to the basic question, but I want to see what other
> people come up with.
>
> --Ken
>
> --
> Ken Bloom. PhD candidate. Linguistic Cognition Laboratory.
> Department of Computer Science. Illinois Institute of Technology.
> http://www.iit.edu...
>
>

I wrote a webapp that did something like that using a perverted
Condorcet method described here: http://xkcd.com/date/algor....
I don't have the code anymore, but that's a concise way fo doing it.

--
Chris Carter
concentrationstudios.com
brynmawrcs.com

Ken Bloom

5/4/2007 4:08:00 AM

On Fri, 04 May 2007 09:41:51 +0900, Bill Guindon wrote:

> On 5/3/07, Ken Bloom <kbloom@gmail.com> wrote:
>> Apparently some people around here can't stand Ruby Quiz withdrawal.
>> For those people, here's a quiz question I just came up with.
>>
>> I have a list of some items, and I would like to manually rank which
>> ones are most important to me. But it's not easy to rank them when I'm
>> looking at them all at once, so I'd like to consider them in pairs and
>> choose from each pair which one is most important to me. Then I'd like
>> to use my answers to those questions to create a ranked list. Anyone
>> think they can come up with a good program to quiz me about these items
>> pairwise, and output a ranking?
>
> Thanks much for filling in. I'm very interested, and I hope I have the
> time to take a shot at this one.
>
> Could you elaborate on the rules a bit? Do all possible pairs have to
> be evaluated, or should it deduce values based on previous answers?
>
> banana is more important than apple
> orange is more important than banana
> no need to compare apples to oranges (pardon the pun).

I guess I'd want to know if I ran into a cycle, but I know that's a lot
more questions. Something else that I would find interesting is having a
way to determine the top 10 asking the minimum number of questions. So
implement whatever answer you prefer.

--Ken

P.S. I think the Ruby Quiz needs a fourth rule: don't ask too many
questions about what the rules of a particular quiz are. Your variation
on the problem may have interesting techniques that nobody else's has.

--
Ken Bloom. PhD candidate. Linguistic Cognition Laboratory.
Department of Computer Science. Illinois Institute of Technology.
http://www.iit.edu...

Clifford Heath

5/4/2007 4:20:00 AM

Ken Bloom wrote:
> I have a list of some items, and I would like to manually rank which ones
> are most important to me. But it's not easy to rank them when I'm looking
> at them all at once, so I'd like to consider them in pairs and choose
> from each pair which one is most important to me.

Topological sort. "man tsort" on most *nix systems, or
<http://en.wikipedia.org/wiki/Topological_sorting#Algo....
The rest is just I/O.

Eric Mahurin

5/6/2007 1:59:00 AM

On 5/3/07, Ken Bloom <kbloom@gmail.com> wrote:
> I have a list of some items, and I would like to manually rank which ones
> are most important to me. But it's not easy to rank them when I'm looking
> at them all at once, so I'd like to consider them in pairs and choose
> from each pair which one is most important to me. Then I'd like to use my
> answers to those questions to create a ranked list. Anyone think they can
> come up with a good program to quiz me about these items pairwise, and
> output a ranking?

The way I see it, ranking is nothing more than sorting and choosing
between pairs is just the comparison of the sort. So, here is a
one-liner given the item list in a file and the questions on stdin:

ruby -e 'puts(ARGF.read.split.sort { |a,b| print "1: #{a}\n2: #{b}\n";
STDIN.gets.to_i*2-3}.inspect)' <item-file>

Eric

Ken Bloom

5/6/2007 3:08:00 PM

On Thu, 03 May 2007 18:49:09 -0500, Ken Bloom wrote:

> Apparently some people around here can't stand Ruby Quiz withdrawal. For
> those people, here's a quiz question I just came up with.
>
> I have a list of some items, and I would like to manually rank which
> ones are most important to me. But it's not easy to rank them when I'm
> looking at them all at once, so I'd like to consider them in pairs and
> choose from each pair which one is most important to me. Then I'd like
> to use my answers to those questions to create a ranked list. Anyone
> think they can come up with a good program to quiz me about these items
> pairwise, and output a ranking?
>
> Extra credit: come up with a solution that lets me take the quiz
> multiple times, and outputs a single ranked list reflecting all of my
> sessions taking the quiz.
>
> I have my solution to the basic question, but I want to see what other
> people come up with.

Here's a solution that uses tsort, the topological sort module from
Ruby's standard library. It asks Theta(n^2) questions, but allows me to
specify that two items on the list are really redundant (and have that
reflected in the output), and to detect cycles in my preferences that I
may need to break somehow.

#!/usr/bin/env ruby
require 'rubygems'
require 'enumerator'
require 'facets/core/enumerable/each_unique_pair'
require 'tsort'

class Hash
include TSort
alias tsort_each_node each_key
def tsort_each_child(node, &block)
fetch(node).each(&block)
end
end

LIST=["Option 1","Option 2","Option 3","Option 4"]
RESULTS=Hash.new{|h,k| h[k]=[]}
LIST.each{|x| RESULTS[x]}

LIST.enum_for(:each_unique_pair).
map{|x| x.sort_by{rand}}.
sort_by{rand}.each do |opt1,opt2|
printf "1:%s 2:%s ",opt1,opt2
case readline.chomp
when "1":
RESULTS[opt2] << opt1
when "2":
RESULTS[opt1] << opt2
when "=":
RESULTS[opt1] << opt2
RESULTS[opt2] << opt1
else
puts "No preference"
end
end

puts

#ORDERED LIST
RESULTS.strongly_connected_components.
each{|list| p list}

--
Ken Bloom. PhD candidate. Linguistic Cognition Laboratory.
Department of Computer Science. Illinois Institute of Technology.
http://www.iit.edu...

comp.lang.ruby

Unofficial Ruby Quiz -- Ranking Choices

Ken Bloom

Bill Guindon

Chris Carter

Ken Bloom

Clifford Heath

Eric Mahurin

Ken Bloom

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