version 1.65, 2003/03/28 18:14:59
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version 1.66, 2003/04/01 16:53:50
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Line 1163 Each hash must contain at least the 'use
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Line 1163 Each hash must contain at least the 'use
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=back |
=back |
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Outputs: See the code for up to date information. |
Outputs: See the code for up to date information. A hash reference is |
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returned. The hash has the following keys defined: |
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=over 4 |
=over 4 |
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=item $num The number of students attempting the problem |
=item num_students The number of students attempting the problem |
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=item tries The total number of tries for the students |
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=item max_tries The maximum number of tries taken |
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=item mean_tries The average number of tries |
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=item num_solved The number of students able to solve the problem |
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=item num_override The number of students whose answer is 'correct_by_override' |
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=item deg_of_diff The degree of difficulty of the problem |
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=item std_tries The standard deviation of the number of tries |
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=item skew_tries The skew of the number of tries |
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=item $tries The total number of tries for the students |
=item per_wrong The number of students attempting the problem who were not |
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able to answer it correctly. |
=item $mod The maximum number of tries taken |
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=item $mean The average number of tries |
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=item $Solved The number of students able to solve the problem |
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=item $solved The number of students whose answer is 'correct_by_override' |
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=item $DegOfDiff The degree of difficulty of the problem |
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=item $STD The standard deviation of the number of tries |
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=item $SKEW The skew of the number of tries |
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=back |
=back |
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Line 1247 sub get_problem_statistics {
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Line 1251 sub get_problem_statistics {
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$solved = 0 if (! defined($solved)); |
$solved = 0 if (! defined($solved)); |
# |
# |
my $DegOfDiff = 'nan'; |
my $DegOfDiff = 'nan'; |
$DegOfDiff = 1-($Solved + $solved)/$tries if ($tries>0); |
$DegOfDiff = 1-($Solved)/$tries if ($tries>0); |
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my $SKEW = 'nan'; |
my $SKEW = 'nan'; |
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my $wrongpercent = 0; |
if ($num > 0) { |
if ($num > 0) { |
($SKEW) = &execute_SQL_request($dbh,'SELECT SQRT(SUM('. |
($SKEW) = &execute_SQL_request($dbh,'SELECT SQRT(SUM('. |
'POWER(tries - '.$STD.',3)'. |
'POWER(tries - '.$STD.',3)'. |
'))/'.$num.' FROM '.$stats_table); |
'))/'.$num.' FROM '.$stats_table); |
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$wrongpercent=int(10*100*($num-$Solved+$solved)/$num)/10; |
} |
} |
# |
# |
$dbh->do('DROP TABLE '.$stats_table); # May return an error |
$dbh->do('DROP TABLE '.$stats_table); # May return an error |
return ($num,$tries,$mod,$mean,$Solved,$solved,$DegOfDiff,$STD,$SKEW); |
return { num_students => $num, |
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tries => $tries, |
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max_tries => $mod, |
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mean_tries => $mean, |
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std_tries => $STD, |
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skew_tries => $SKEW, |
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num_solved => $Solved, |
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num_override => $solved, |
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per_wrong => $wrongpercent, |
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deg_of_diff => $DegOfDiff } |
} |
} |
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sub execute_SQL_request { |
sub execute_SQL_request { |