#!/usr/bin/perl

use strict;
use warnings;
use Data::Dumper;

my @array =
(
    { utterance => 'ja', score => 0.27 },
    { utterance => 'nein', score => 0.75 },
    { utterance => 'nein', score => 0.83 },
    { utterance => 'ja', score => 0.53 },
    { utterance => 'ja', score => 0.69 },
    { utterance => 'nicht wirklich', score => 0.59 },
);

my %result;

for my $elem(@array){
    my $key = $elem->{utterance};
    my $score = $elem->{score};
    $result{$key} = {score => 0, max_score => 0, min_score => 10_000} unless exists $result{$key};
    $result{$key}->{score} += $score;
    if($result{$key}->{max_score} < $score){
        $result{$key}->{max_score} = $score;
    }
    
    if($result{$key}->{min_score} > $score){
        $result{$key}->{min_score} = $score;
    }
    
}

print Dumper(\%result);

~/entwicklung 135> perl scores.pl 
$VAR1 = {
          'nein' => {
                      'max_score' => '0.83',
                      'score' => '1.58',
                      'min_score' => '0.75'
                    },
          'nicht wirklich' => {
                                'max_score' => '0.59',
                                'score' => '0.59',
                                'min_score' => '0.59'
                              },
          'ja' => {
                    'max_score' => '0.69',
                    'score' => '1.49',
                    'min_score' => '0.27'
                  }
        };