File:  [LON-CAPA] / loncom / interface / statistics / lonproblemstatistics.pm
Revision 1.24: download - view: text, annotated - select for diffs
Wed Aug 14 13:13:37 2002 UTC (21 years, 11 months ago) by stredwic
Branches: MAIN
CVS tags: HEAD
Discriminant factors now work again.

    1: # The LearningOnline Network with CAPA
    2: # (Publication Handler
    3: #
    4: # $Id: lonproblemstatistics.pm,v 1.24 2002/08/14 13:13:37 stredwic Exp $
    5: #
    6: # Copyright Michigan State University Board of Trustees
    7: #
    8: # This file is part of the LearningOnline Network with CAPA (LON-CAPA).
    9: #
   10: # LON-CAPA is free software; you can redistribute it and/or modify
   11: # it under the terms of the GNU General Public License as published by
   12: # the Free Software Foundation; either version 2 of the License, or
   13: # (at your option) any later version.
   14: #
   15: # LON-CAPA is distributed in the hope that it will be useful,
   16: # but WITHOUT ANY WARRANTY; without even the implied warranty of
   17: # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   18: # GNU General Public License for more details.
   19: #
   20: # You should have received a copy of the GNU General Public License
   21: # along with LON-CAPA; if not, write to the Free Software
   22: # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   23: #
   24: # /home/httpd/html/adm/gpl.txt
   25: #
   26: # http://www.lon-capa.org/
   27: #
   28: # (Navigate problems for statistical reports
   29: # YEAR=2001
   30: # 5/5,7/9,7/25/1,8/11,9/13,9/26,10/5,10/9,10/22,10/26 Behrouz Minaei
   31: # 11/1,11/4,11/16,12/14,12/16,12/18,12/20,12/31 Behrouz Minaei
   32: # YEAR=2002
   33: # 1/22,2/1,2/6,2/25,3/2,3/6,3/17,3/21,3/22,3/26,4/7,5/6 Behrouz Minaei
   34: # 5/12,5/14,5/15,5/19,5/26,7/16,7/25,7/29,8/5  Behrouz Minaei
   35: #
   36: ###
   37: 
   38: package Apache::lonproblemstatistics; 
   39: 
   40: use strict;
   41: use Apache::lonnet();
   42: use Apache::lonhtmlcommon;
   43: use Apache::loncoursedata;
   44: use GDBM_File;
   45: 
   46: my $jr;
   47: 
   48: sub BuildProblemStatisticsPage {
   49:     my ($cacheDB, $students, $courseID, $c, $r)=@_;
   50:     my %cache;
   51: 
   52:     $jr = $r;
   53: 
   54:     unless(tie(%cache,'GDBM_File',$cacheDB,&GDBM_READER(),0640)) {
   55:         $r->print('Unable to tie database.');
   56:         return;
   57:     }
   58: 
   59:     my $Ptr = '';
   60:     $Ptr .= '<table border="0"><tbody>';
   61:     $Ptr .= '<tr><td align="right"><b>Select Map</b></td>'."\n";
   62:     $Ptr .= '<td align="left">';
   63:     $Ptr .= &Apache::lonhtmlcommon::MapOptions(\%cache, 'ProblemStatistics',
   64:                                                'Statistics');
   65:     $Ptr .= '</td></tr>'."\n";
   66:     $Ptr .= '<tr><td align="right"><b>Sorting Type:</b></td>'."\n";
   67:     $Ptr .= '<td align="left">'."\n";
   68:     $Ptr .= &Apache::lonhtmlcommon::AscendOrderOptions(
   69:                                             $cache{'ProblemStatisticsAscend'}, 
   70:                                             'ProblemStatistics',
   71:                                             'Statistics');
   72:     $Ptr .= '</td></tr>'."\n";
   73:     $Ptr .= &ProblemStatisticsButtons($cache{'DisplayFormat'}, 
   74:                                       $cache{'DisplayLegend'});
   75:     $Ptr .= '</table>';
   76:     if($cache{'DisplayLegend'} eq 'Show Legend') {
   77:         $Ptr .= &ProblemStatisticsLegend();
   78:     }
   79:     $r->print($Ptr);
   80:     $r->rflush();
   81: 
   82:     my @Header = ("Homework Sets Order","#Stdnts","Tries","Mod",
   83:                   "Mean","#YES","#yes","%Wrng","DoDiff",
   84:                   "S.D.","Skew.","D.F.1st","D.F.2nd","Disc.");
   85:     my $color=&setbgcolor(0);
   86: 
   87: #    my %Discuss=&Apache::loncoursedata::LoadDiscussion($courseID);
   88: #    my ($upper, $lower) = &Discriminant(\%discriminant,$r);
   89:     if(!defined($cache{'StatisticsCached'})) {
   90:         if(defined($cache{'StatisticsCached'})) {
   91:             untie(%cache);
   92:             unless(tie(%cache,'GDBM_File',$cacheDB,&GDBM_WRCREAT(),0640)) {
   93:                 $r->print('Unable to tie database.');
   94:                 return;
   95:             }
   96:             my @statkeys = split(':::', $cache{'StatisticsKeys'});
   97:             delete $cache{'StatisticsKeys'};
   98:             delete $cache{'StatisticsCached'};
   99:             foreach(@statkeys) {
  100:                 delete $cache{$_};
  101:             }
  102:         }
  103:         untie(%cache);
  104:         &Apache::loncoursedata::DownloadStudentCourseDataSeparate($students,
  105:                                                                   'true',
  106:                                                                   $cacheDB,
  107:                                                                   'true', 
  108:                                                                   'true',
  109:                                                                   $courseID,
  110:                                                                   $r, $c);
  111:         if($c->aborted()) { return; }
  112: 
  113:         unless(tie(%cache,'GDBM_File',$cacheDB,&GDBM_READER(),0640)) {
  114:             $r->print('Unable to tie database.');
  115:             return;
  116:         }
  117:         my ($problemData) = &ExtractStudentData(\%cache, $students);
  118:         &CalculateStatistics($problemData, \%cache);
  119:         untie(%cache);
  120: 
  121:         unless(tie(%cache,'GDBM_File',$cacheDB,&GDBM_WRCREAT(),0640)) {
  122:             $r->print('Unable to tie database.');
  123:             return;
  124:         }
  125:         foreach(keys(%$problemData)) {
  126:             $cache{$_} = $problemData->{$_};
  127:         }
  128:         $cache{'StatisticsKeys'} = join(':::', keys(%$problemData));
  129:         $cache{'StatisticsCached'} = 'true';
  130:         untie(%cache);
  131: 
  132:         unless(tie(%cache,'GDBM_File',$cacheDB,&GDBM_READER(),0640)) {
  133:             $r->print('Unable to tie database.');
  134:             return;
  135:         }
  136:     }
  137:     my $orderedProblems = &SortProblems(\%cache, 
  138:                                         $cache{'ProblemStatisticsSort'},
  139:                                         $cache{'ProblemStatisticsAscend'});
  140:     &BuildStatisticsTable(\%cache, $cache{'DisplayFormat'}, $orderedProblems, 
  141:                           \@Header, $r, $color);
  142:     untie(%cache);
  143: 
  144:     return;
  145: }
  146: 
  147: sub BuildGraphicChart {
  148:     my ($graph,$cacheDB,$courseDescription,$r)=@_;
  149:     my %cache;
  150:     my $max = 0;
  151: 
  152:     unless(tie(%cache,'GDBM_File',$cacheDB,&GDBM_READER(),0640)) {
  153:         return '<html><body>Unable to tie database.</body></html>';
  154:     }
  155:    
  156:     my @problems = split(':::', $cache{'problemList'});
  157:     my @values = ();
  158:     foreach (@problems) {
  159:         my $data = 0;
  160:         if($graph eq 'DoDiffGraph') {
  161:             $data = sprintf("%.2f", $cache{$_.':degreeOfDifficulty'}),
  162:         } else {
  163:             $data = sprintf("%.1f", $cache{$_.':percentWrong'}),
  164:         }
  165:         if($max < $data) {
  166:             $max = $data;
  167:         }
  168:         push(@values, $data);
  169:     }
  170:     untie(%cache);
  171: 
  172:     my $sendValues = join(',', @values);
  173: #    my $sendCount = $#values;
  174:     my $sendCount = scalar(@values);
  175: 
  176:     my $title = '';
  177:     if($graph eq 'DoDiffGraph') {
  178: 	$title = 'Degree-of-Difficulty';
  179:     } else {
  180: 	$title = 'Wrong-Percentage';
  181:     }
  182:     my @GData = ($courseDescription, 'Problems', $title, $max, $sendCount, 
  183:                  $sendValues);
  184: 
  185:     $r->print('</form>'."\n");
  186:     $r->print('<IMG src="/cgi-bin/graph.gif?'.(join('&', @GData)).'" border="1" />');
  187:     $r->print('<form>'."\n");
  188: 
  189:     return;
  190: }
  191: 
  192: #---- Problem Statistics Web Page ---------------------------------------
  193: 
  194: sub CreateProblemStatisticsTableHeading {
  195:     my ($headings,$r)=@_;
  196: 
  197:     my $Str='';
  198:     $Str .= '<tr>'."\n";
  199:     $Str .= '<th bgcolor="#ffffe6">P#</th>'."\n";
  200:     foreach(@$headings) {
  201: 	$Str .= '<th bgcolor="#ffffe6">'.'<a href="/adm/statistics?reportSelected=';
  202:         $Str .= &Apache::lonnet::escape('Problem Statistics');
  203:         $Str .= '&ProblemStatisticsSort=';
  204:         $Str .= &Apache::lonnet::escape($_).'">'.$_.'</a>&nbsp</th>'."\n";
  205:     }
  206:     $Str .= "\n".'</tr>'."\n";    
  207: 
  208:     return $Str;
  209: }
  210: 
  211: sub BuildStatisticsTable {
  212:     my ($cache,$displayFormat,$orderedProblems,$headings,$r,$color)=@_;
  213: 
  214: #6666666
  215: #    my $file="/home/httpd/perl/tmp/183d.txt";
  216: #    open(OUT, ">$file");
  217: #6666666
  218: ##     &Apache::lonstatistics::Create_PrgWin($r);
  219: ##777777
  220: ##    my (%Activity) = &LoadActivityLog();
  221: ##    $r->print('<script>popwin.document.popremain.remaining.value="'.
  222: ##              'Loading Discussion...";</script>');
  223: ##    my ($doDiffFile) = &LoadDoDiffFile();
  224: 
  225: ##777777
  226: ##    $Str .= &Classify($discriminantFactor, $students);
  227: 
  228:      if($displayFormat ne 'Display CSV Format') {
  229:         $r->print('<table border="0"><tr><td bgcolor="#777777">'."\n");
  230:         $r->print('<table border="0" cellpadding="3">'."\n");
  231:         $r->print(&CreateProblemStatisticsTableHeading($headings, $r));
  232:     } else {
  233:         $r->print('<br>');
  234:     }
  235: 
  236:     my $count = 1;
  237:     foreach(@$orderedProblems) {
  238:         my ($sequence,$problem,$part)=split(':', $_);
  239:         if($cache->{'ProblemStatisticsMaps'} ne 'All Maps'  &&
  240:            $cache->{'ProblemStatisticsMaps'} ne $cache->{$sequence.':title'}) {
  241:             next;
  242:         }
  243: 
  244:         my $ref = '<a href="'.$cache->{$problem.':source'}.
  245:                   '" target="_blank">'.$cache->{$problem.':title'}.'</a>';
  246: #        my $ref = $cache->{$problem.':title'};
  247:         my $title = $cache->{$problem.':title'};
  248:         my $source = 'source';
  249:         my $tableData = join('&', $ref, $title, $source,
  250:                        $cache->{$_.':studentCount'},
  251:                        $cache->{$_.':totalTries'},
  252:                        $cache->{$_.':maxTries'},
  253:                        sprintf("%.2f", $cache->{$_.':mean'}),
  254:                        $cache->{$_.':correct'},
  255:                        $cache->{$_.':correctByOverride'},
  256:                        sprintf("%.1f", $cache->{$_.':percentWrong'}),
  257:                        sprintf("%.2f", $cache->{$_.':degreeOfDifficulty'}),
  258:                        sprintf("%.1f", $cache->{$_.':standardDeviation'}),
  259:                        sprintf("%.1f", $cache->{$_.':skewness'}),
  260:                        sprintf("%.2f", $cache->{$_.':discriminationFactor1'}),
  261:                        sprintf("%.2f", $cache->{$_.':discriminationFactor2'}),
  262:                        0); # 0 is for discussion, need to figure out
  263: 
  264: #6666666
  265: #	    $r->print('<br>'.$out.'&'.$DoD);
  266: #            print (OUT $out.'@'.$DoD.'&');
  267: #6666666
  268: 
  269: #check with Gerd
  270: #        $urlres=~/^(\w+)\/(\w+)/;
  271: #        if ($StdNo) {
  272: #            &Apache::lonnet::put('nohist_resevaldata',\%storestats,
  273: #                                 $1,$2);
  274: #        }
  275: #-------------------------------- Row of statistical table
  276:         &TableRow($displayFormat,$tableData,$count,$r,$color);
  277:         $count++;
  278:     }
  279:     if($cache->{'DisplayFormat'} ne 'Display CSV Format') {
  280:         $r->print('</table>'."\n");
  281:     }
  282:     $r->print('</td></tr></table>');
  283: #6666666
  284: #    close( OUT );
  285: #666666
  286:     return;
  287: }
  288: 
  289: sub TableRow {
  290:     my ($displayFormat,$Str,$RealIdx,$r,$color)=@_;
  291:     my($ref,$title,$source,$StdNo,$TotalTries,$MxTries,$Avg,$YES,$Override,
  292:        $Wrng,$DoD,$SD,$Sk,$_D1,$_D2,$DiscNo,$Prob)=split(/\&/,$Str);	
  293:     my $Ptr;
  294:     if($displayFormat eq 'Display CSV Format') {
  295:         $Ptr="\n".'<br>'.
  296:              "\n".'"'.$RealIdx.'",'.
  297:              "\n".'"'.$title.'",'.
  298:              "\n".'"'.$source.'",'.
  299:              "\n".'"'.$StdNo.'",'.
  300:              "\n".'"'.$TotalTries.'",'.
  301:              "\n".'"'.$MxTries.'",'.
  302:              "\n".'"'.$Avg.'",'.
  303:              "\n".'"'.$YES.'",'.
  304:              "\n".'"'.$Override.'",'.
  305:              "\n".'"'.$Wrng.'",'.
  306:              "\n".'"'.$DoD.'",'.
  307:              "\n".'"'.$SD.'",'.
  308:              "\n".'"'.$Sk.'",'.
  309:              "\n".'"'.$_D1.'",'.
  310: 	     "\n".'"'.$_D2.'"'.
  311: 	     "\n".'"'.$DiscNo.'"';
  312: 
  313:         $r->print("\n".$Ptr);
  314:     } else {
  315:         $Ptr="\n".'<tr>'.
  316:              "\n".'<td bgcolor="#ffffe6">'.$RealIdx.'</td>'.
  317:              "\n".'<td bgcolor="#ffffe6">'.$ref.'</td>'.
  318:              "\n".'<td bgcolor='.$color->{"yellow"}.'> '.$StdNo.'</td>'.
  319:              "\n".'<td bgcolor='.$color->{"yellow"}.'>'.$TotalTries.'</td>'.
  320:              "\n".'<td bgcolor='.$color->{"yellow"}.'>'.$MxTries.'</td>'.
  321:              "\n".'<td bgcolor='.$color->{"gb"}.'>'.$Avg.'</td>'.
  322:              "\n".'<td bgcolor='.$color->{"gb"}.'> '.$YES.'</td>'.
  323:              "\n".'<td bgcolor='.$color->{"gb"}.'> '.$Override.'</td>'.
  324:              "\n".'<td bgcolor='.$color->{"red"}.'> '.$Wrng.'</td>'.
  325:              "\n".'<td bgcolor='.$color->{"red"}.'> '.$DoD.'</td>'.
  326:              "\n".'<td bgcolor='.$color->{"green"}.'> '.$SD.'</td>'.
  327:              "\n".'<td bgcolor='.$color->{"green"}.'> '.$Sk.'</td>'.
  328:              "\n".'<td bgcolor='.$color->{"purple"}.'> '.$_D1.'</td>'.
  329: 	     "\n".'<td bgcolor='.$color->{"purple"}.'> '.$_D2.'</td>'.
  330:              "\n".'<td bgcolor='.$color->{"yellow"}.'> '.$DiscNo.'</td>';
  331:         $r->print("\n".$Ptr.'</tr>' );
  332:     }
  333: 
  334:     return;
  335: }
  336: 
  337: # For loading the colored table for display or un-colored for print
  338: sub setbgcolor {
  339:     my $PrintTable=shift;
  340:     my %color;
  341:     if ($PrintTable){
  342: 	$color{"gb"}="#FFFFFF";
  343: 	$color{"red"}="#FFFFFF";
  344: 	$color{"yellow"}="#FFFFFF";
  345: 	$color{"green"}="#FFFFFF";
  346: 	$color{"purple"}="#FFFFFF";
  347:     } else {
  348: 	$color{"gb"}="#DDFFFF";
  349: 	$color{"red"}="#FFDDDD";
  350: 	$color{"yellow"}="#EEFFCC";
  351: 	$color{"green"}="#DDFFDD";
  352: 	$color{"purple"}="#FFDDFF";
  353:     }
  354: 
  355:     return \%color;
  356: }
  357: 
  358: sub ProblemStatisticsButtons {
  359:     my ($displayFormat, $displayLegend)=@_;
  360: 
  361:     my $Ptr = '<tr><td></td><td align="left">';
  362:     $Ptr .= '<input type="submit" name="DoDiffGraph" ';
  363:     $Ptr .= 'value="DoDiff Graph" />'."\n";
  364:     $Ptr .= '&nbsp;&nbsp;&nbsp;';
  365:     $Ptr .= '<input type="submit" name="PercentWrongGraph" ';
  366:     $Ptr .= 'value="%Wrong Graph" />'."\n";
  367:     $Ptr .= '</td></tr><tr><td></td><td>'."\n";
  368:     $Ptr .= '<input type="submit" name="DisplayLegend" ';
  369:     if($displayLegend eq 'Show Legend') {
  370:         $Ptr .= 'value="Hide Legend" />'."\n";
  371:     } else {
  372:         $Ptr .= 'value="Show Legend" />'."\n";
  373:     }
  374:     $Ptr .= '&nbsp;&nbsp;&nbsp;';
  375:     $Ptr .= '<input type="submit" name="DisplayCSVFormat" ';
  376:     if($displayFormat eq 'Display CSV Format') {
  377:         $Ptr .= 'value="Display Table Format" />'."\n";
  378:     } else {
  379:         $Ptr .= 'value="Display CSV Format" />'."\n";
  380:     }
  381:     $Ptr .= '</td></tr>';
  382: 
  383:     return $Ptr;
  384: }
  385: 
  386: sub ProblemStatisticsLegend {
  387:     my $Ptr = '';
  388:     $Ptr = '<table border="0">';
  389:     $Ptr .= '<tr><td>';
  390:     $Ptr .= '<b>#Stdnts</b></td>';
  391:     $Ptr .= '<td>Total number of students attempted the problem.';
  392:     $Ptr .= '</td></tr><tr><td>';
  393:     $Ptr .= '<b>Tries</b></td>';
  394:     $Ptr .= '<td>Total number of tries for solving the problem.';
  395:     $Ptr .= '</td></tr><tr><td>';
  396:     $Ptr .= '<b>Mod</b></td>';
  397:     $Ptr .= '<td>Largest number of tries for solving the problem by a student.';
  398:     $Ptr .= '</td></tr><tr><td>';
  399:     $Ptr .= '<b>Mean</b></td>';
  400:     $Ptr .= '<td>Average number of tries. [ Tries / #Stdnts ]';
  401:     $Ptr .= '</td></tr><tr><td>';
  402:     $Ptr .= '<b>#YES</b></td>';
  403:     $Ptr .= '<td>Number of students solved the problem correctly.';
  404:     $Ptr .= '</td></tr><tr><td>';
  405:     $Ptr .= '<b>#yes</b></td>';
  406:     $Ptr .= '<td>Number of students solved the problem by override.';
  407:     $Ptr .= '</td></tr><tr><td>';
  408:     $Ptr .= '<b>%Wrong</b></td>';
  409:     $Ptr .= '<td>Percentage of students who tried to solve the problem ';
  410:     $Ptr .= 'but is still incorrect. [ 100*((#Stdnts-(#YES+#yes))/#Stdnts) ]';
  411:     $Ptr .= '</td></tr><tr><td>';
  412:     $Ptr .= '<b>DoDiff</b></td>';
  413:     $Ptr .= '<td>Degree of Difficulty of the problem.  ';
  414:     $Ptr .= '[ 1 - ((#YES+#yes) / Tries) ]';
  415:     $Ptr .= '</td></tr><tr><td>';
  416:     $Ptr .= '<b>S.D.</b></td>';
  417:     $Ptr .= '<td>Standard Deviation of the tries.  ';
  418:     $Ptr .= '[ sqrt(sum((Xi - Mean)^2)) / (#Stdnts-1) ';
  419:     $Ptr .= 'where Xi denotes every student\'s tries ]';
  420:     $Ptr .= '</td></tr><tr><td>';
  421:     $Ptr .= '<b>Skew.</b></td>';
  422:     $Ptr .= '<td>Skewness of the students tries.';
  423:     $Ptr .= '[(sqrt( sum((Xi - Mean)^3) / #Stdnts)) / (S.D.^3)]';
  424:     $Ptr .= '</td></tr><tr><td>';
  425:     $Ptr .= '<b>Dis.F.</b></td>';
  426:     $Ptr .= '<td>Discrimination Factor: A Standard for evaluating the ';
  427:     $Ptr .= 'problem according to a Criterion<br>';
  428:     $Ptr .= '<b>[Applied Criterion in %27 Upper Students - ';
  429:     $Ptr .= 'Applied the same Criterion in %27 Lower Students]</b><br>';
  430:     $Ptr .= '<b>1st Criterion</b> for Sorting the Students: ';
  431:     $Ptr .= '<b>Sum of Partial Credit Awarded / Total Number of Tries</b><br>';
  432:     $Ptr .= '<b>2nd Criterion</b> for Sorting the Students: ';
  433:     $Ptr .= '<b>Total number of Correct Answers / Total Number of Tries</b>';
  434:     $Ptr .= '</td></tr>';
  435:     $Ptr .= '<tr><td><b>Disc.</b></td>';
  436:     $Ptr .= '<td>Number of Students had at least one discussion.';
  437:     $Ptr .= '</td></tr></table>';
  438: 
  439:     return $Ptr;
  440: }
  441: 
  442: #------- Processing upperlist and lowerlist according to each problem
  443: 
  444: sub ExtractStudentData {
  445:     my ($cache, $students)=@_;
  446: 
  447: #$Apache::lonxml::debug=1;
  448: #&Apache::lonhomework::showhash(%$cache);
  449: #$Apache::lonxml::debug=0;
  450: 
  451:     my @problemList=();
  452:     my %problemData;
  453:     foreach my $sequence (split(':', $cache->{'orderedSequences'})) {
  454:         foreach my $problemID (split(':', $cache->{$sequence.':problems'})) {
  455:             foreach my $part (split(/\:/,$cache->{$sequence.':'.
  456:                                                   $problemID.
  457:                                                   ':parts'})) {
  458:                 my $id = $sequence.':'.$problemID.':'.$part;
  459:                 push(@problemList, $id);
  460:                 my $totalTries = 0;
  461:                 my $totalAwarded = 0;
  462:                 my $correct = 0;
  463:                 my $correctByOverride = 0;
  464:                 my $studentCount = 0;
  465:                 my $maxTries = 0;
  466:                 my $totalFirst = 0;
  467:                 my @studentTries=();
  468:                 foreach(@$students) {
  469:                     my $code = $cache->{"$_:$problemID:$part:code"};
  470: 
  471:                     if(defined($cache->{$_.':error'}) || $code eq ' ' ||
  472:                        $cache->{"$_:$problemID:NoVersion"} eq 'true') {
  473:                         next;
  474:                     }
  475: 
  476:                     $studentCount++;
  477:                     my $tries =  $cache->{"$_:$problemID:$part:tries"};
  478:                     if($maxTries < $tries) {
  479:                         $maxTries = $tries;
  480:                     }
  481:                     $totalTries += $tries;
  482:                     push(@studentTries, $tries);
  483: 
  484:                     my $awarded = $cache->{"$_:$problemID:$part:awarded"};
  485:                     $totalAwarded += $awarded;
  486: 
  487:                     if($code eq '*') {
  488:                         $correct++;
  489:                         if($tries == 1) {
  490:                             $totalFirst++;
  491:                         }
  492:                     } elsif($code eq '+') {
  493:                         $correctByOverride++;
  494:                     }
  495:                 }
  496: 
  497:                 $problemData{$id.':sequenceTitle'} = 
  498:                     $cache->{$sequence.':title'};
  499:                 $problemData{$id.':studentCount'} = $studentCount;
  500:                 $problemData{$id.':totalTries'} = $totalTries;
  501:                 $problemData{$id.':studentTries'} = \@studentTries;
  502:                 $problemData{$id.':totalAwarded'} = $totalAwarded;
  503:                 $problemData{$id.':correct'} = $correct;
  504:                 $problemData{$id.':correctByOverride'} = $correctByOverride;
  505:                 $problemData{$id.':wrong'} = $studentCount - 
  506:                                              ($correct + $correctByOverride);
  507:                 $problemData{$id.':maxTries'} = $maxTries;
  508:                 $problemData{$id.':totalFirst'} = $totalFirst;
  509:             }
  510:         }
  511:     }
  512: 
  513:     my @upperStudents1=();
  514:     my @lowerStudents1=();
  515:     my @upperStudents2=();
  516:     my @lowerStudents2=();
  517:     my $upperCount = int(0.27*scalar(@$students));
  518:     # Discriminant Factor criterion 1
  519:     my $sortedStudents = &SortDivideByTries($students,$cache,':totalAwarded');
  520: 
  521:     for(my $i=0; $i<$upperCount; $i++) {
  522:         push(@lowerStudents1, $sortedStudents->[$i]);
  523:         push(@upperStudents1, $sortedStudents->[(scalar(@$students)-$i-1)]);
  524:     }
  525: 
  526:     $problemData{'studentsUpperListCriterion1'}=join(':::', @upperStudents1);
  527:     $problemData{'studentsLowerListCriterion1'}=join(':::', @lowerStudents1);
  528: 
  529:     # Discriminant Factor criterion 2
  530:     $sortedStudents = &SortDivideByTries($students, $cache, ':totalSolved');
  531: 
  532:     for(my $i=0; $i<$upperCount; $i++) {
  533:         push(@lowerStudents2, $sortedStudents->[$i]);
  534:         push(@upperStudents2, $sortedStudents->[(scalar(@$students)-$i-1)]);
  535:     }
  536:     $problemData{'studentsUpperListCriterion2'}=join(':::', @upperStudents2);
  537:     $problemData{'studentsLowerListCriterion2'}=join(':::', @lowerStudents2);
  538: 
  539:     $problemData{'problemList'} = join(':::', @problemList);
  540: #                $Discussed=0;
  541: #                if($Discuss->{"$name:$problem"}) {
  542: #		    $TotDiscuss++;
  543: #                    $Discussed=1;
  544: #                }
  545: 
  546:     return \%problemData;
  547: }
  548: 
  549: sub SortDivideByTries {
  550:     my ($toSort, $data, $sortOn)=@_;
  551:     my @orderedData = sort { ($data->{$a.':totalTries'}) ? 
  552:                              ($data->{$a.$sortOn}/$data->{$a.':totalTries'}):0
  553:                              <=>
  554:                              ($data->{$b.':totalTries'}) ? 
  555:                              ($data->{$b.$sortOn}/$data->{$b.':totalTries'}):0
  556:                            } @$toSort;
  557: 
  558:     return \@orderedData;
  559: }
  560: 
  561: sub SortProblems {
  562:     my ($problemData,$sortBy,$ascend)=@_;
  563: 
  564:     my @problems = split(':::', $problemData->{'problemList'});
  565:     if($sortBy eq "Homework Sets Order") {
  566:         return \@problems;
  567:     }
  568: 
  569:     my $data;
  570: 
  571:     if   ($sortBy eq "#Stdnts") { $data = ':studentCount'; }
  572:     elsif($sortBy eq "Tries")   { $data = ':totalTries'; }
  573:     elsif($sortBy eq "Mod")     { $data = ':maxTries'; }
  574:     elsif($sortBy eq "Mean")    { $data = ':mean'; }
  575:     elsif($sortBy eq "#YES")    { $data = ':correct'; }
  576:     elsif($sortBy eq "#yes")    { $data = ':correctByOverride'; }
  577:     elsif($sortBy eq "%Wrng")   { $data = ':percentWrong'; }
  578:     elsif($sortBy eq "DoDiff")  { $data = ':degreeOfDifficulty'; }
  579:     elsif($sortBy eq "S.D.")    { $data = ':standardDeviation'; }
  580:     elsif($sortBy eq "Skew.")   { $data = ':skewness'; }
  581:     elsif($sortBy eq "D.F.1st") { $data = ':discriminantFactor1'; }
  582:     elsif($sortBy eq "D.F.2nd") { $data = ':discriminantFactor2'; }
  583:     elsif($sortBy eq "Disc.")   { $data = ''; }
  584:     else                        { return \@problems; }
  585: 
  586:     my @orderedProblems = 
  587:         sort { $problemData->{$a.$data} <=> $problemData->{$b.$data} }
  588:              @problems;
  589:     if($ascend eq 'Descending') {
  590:         @orderedProblems = reverse(@orderedProblems);
  591:     }
  592: 
  593:     return \@orderedProblems;
  594: }
  595: 
  596: sub CalculateStatistics {
  597:     my ($data, $cache)=@_;
  598: 
  599:     my @problems = split(':::', $data->{'problemList'});
  600:     foreach(@problems) {
  601:         # Mean
  602:         $data->{$_.':mean'} = ($data->{$_.':studentCount'}) ? 
  603:             ($data->{$_.':totalTries'} / $data->{$_.':studentCount'}) : 0;
  604: 
  605:         # %Wrong
  606:         $data->{$_.':percentWrong'} = ($data->{$_.':studentCount'}) ?
  607:             (($data->{$_.':wrong'} / $data->{$_.':studentCount'}) * 100.0) : 
  608:             100.0;
  609: 
  610:         # Degree of Difficulty
  611:         $data->{$_.':degreeOfDifficulty'} = ($data->{$_.':totalTries'}) ?
  612:             (1 - (($data->{$_.':correct'} + $data->{$_.':correctByOverride'}) /
  613:                   $data->{$_.':totalTries'})) : 0;
  614: 
  615:         # Factor in mean
  616:         my $studentTries = $data->{$_.':studentTries'};
  617:         foreach(my $index=0; $index < scalar(@$studentTries); $index++) {
  618:             $studentTries->[$index] -= $data->{$_.':mean'};
  619:         }
  620:         my $sumSquared = 0;
  621:         my $sumCubed = 0;
  622:         foreach(@$studentTries) {
  623:             my $squared = ($_ * $_);
  624:             my $cubed = ($squared * $_);
  625:             $sumSquared += $squared;
  626:             $sumCubed += $cubed;
  627:         }
  628: 
  629:         # Standard deviation
  630:         $data->{$_.':standardDeviation'} = ($data->{$_.':studentCount'} - 1) ?
  631:             ((sqrt($sumSquared)) / ($data->{$_.':studentCount'} - 1)) : 0;
  632: 
  633:         # Skewness
  634:         my $standardDeviation = $data->{$_.':standardDeviation'};
  635:         $data->{$_.':skewness'} = ($data->{$_.':standardDeviation'}) ?
  636:             (((sqrt($sumSquared)) / $data->{$_.':studentCount'}) / 
  637:              ($standardDeviation * $standardDeviation * $standardDeviation)) :
  638:              0;
  639: 
  640:         # Discrimination Factor 1
  641:         my ($sequence, $problem, $part) = split(':', $_);
  642: 
  643:         my @upper1 = split(':::', $data->{'studentsUpperListCriterion1'});
  644:         my @lower1 = split(':::', $data->{'studentsLowerListCriterion1'});
  645: 
  646:         my $upper1Sum=0;
  647:         foreach my $name (@upper1) {
  648:             $upper1Sum += $cache->{"$name:$problem:$part:awarded"};
  649:         }
  650:         $upper1Sum /= (scalar(@upper1)) ? (scalar(@upper1)) : 0;
  651: 
  652:         my $lower1Sum=0;
  653:         foreach my $name (@lower1) {
  654:             $lower1Sum += $cache->{"$name:$problem:$part:awarded"};
  655:         }
  656:         $lower1Sum /= (scalar(@lower1)) ? (scalar(@lower1)) : 0;
  657: 
  658:         $data->{$_.':discriminationFactor1'} = $upper1Sum - $lower1Sum;
  659: 
  660:         # Discrimination Factor 2
  661:         my @upper2 = split(':::', $data->{'studentsUpperListCriterion2'});
  662:         my @lower2 = split(':::', $data->{'studentsLowerListCriterion2'});
  663: 
  664:         my $upper2Sum=0;
  665:         foreach my $name (@upper2) {
  666:             $upper2Sum += $cache->{"$name:$problem:$part:awarded"};
  667:         }
  668:         $upper2Sum /= (scalar(@upper2)) ? (scalar(@upper2)) : 0;
  669: 
  670:         my $lower2Sum=0;
  671:         foreach my $name (@lower2) {
  672:             $lower2Sum += $cache->{"$name:$problem:$part:awarded"};
  673:         }
  674:         $lower2Sum /= (scalar(@lower2)) ? (scalar(@lower2)) : 0;
  675: 
  676:         $data->{$_.':discriminationFactor2'} = $upper2Sum - $lower2Sum;
  677:     }
  678: 
  679:     return;
  680: }
  681: 
  682: #---- END Problem Statistics Web Page ----------------------------------------
  683: 
  684: 1;
  685: __END__

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