Here's an artificial test data generator, for those of you who are interested in doing your own benchmarking before publishing your methods. 
my %Items;

sub build_test_data
{
    # reproduceable case
    srand(12345);

    # Sorted by prevalence.  Keyword 'kaa' is way more common than 'kz
+z'.
    my @Keywords = 'kaa' ... 'kzz';

    # Each node is associated with an asciibetical list of unique keyw
+ords.
    # We groom out the top keywords which are basically noise.
    for my $xx ('iaa' .. 'izz')
    {
    my $count = int(rand(8)) + 4;
    $Items{$xx}{$Keywords[ int(rand()*rand()*@Keywords) ]}++
        while $count--;
    delete $Items{$xx}{$_} for 'kaa'..'kab';
    $Items{$xx} = [ sort keys %{$Items{$xx}} ];
    }

    return unless @_;
    print Dumper \%Items; # lots of raw data!
}

build_test_data();

[download]
Update: Here's a useful results format: 
tuples of 3:
6 kaa kdf kea
6 kab kaf kka
4 kad kfa kfg
 ...
tuples of 2:
9 kad kfa
8 kaj kda
8 kaj kda
 ...

[download]

--
[ e d @ h a l l e y . c c ]

In reply to Re: algorithm for 'best subsets' by halley
in thread algorithm for 'best subsets' by halley

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