function qstats($questions, $s, $sumgradesavg){
$this->s = $s;
$this->sumgradesavg = $sumgradesavg;
+
foreach (array_keys($questions) as $qid){
$questions[$qid]->_stats = $this->stats_init_object();
}
$statsinit->othergradevariancesum = 0;
$statsinit->covariancesum = 0;
$statsinit->covariancemaxsum = 0;
+ $statsinit->subquestion = false;
+ $statsinit->subquestions = '';
$statsinit->covariancewithoverallgradesum = 0;
$statsinit->gradearray = array();
$statsinit->othergradesarray = array();
return $statsinit;
}
- function get_records($fromqa, $whereqa, $usingattempts, $qaparams){
+ function get_records($quizid, $currentgroup, $groupstudents, $allattempts){
global $DB;
+ list($fromqa, $whereqa, $qaparams) = quiz_report_attempts_sql($quizid, $currentgroup, $groupstudents, $allattempts);
$sql = 'SELECT qs.id, ' .
'qs.question, ' .
'qa.sumgrades, ' .
$fromqa.' '.
'WHERE ' .$whereqa.
'AND qns.attemptid = qa.uniqueid '.
- $usingattempts.
'AND qns.newgraded = qs.id';
$this->states = $DB->get_records_sql($sql, $qaparams);
if ($this->states === false){
$stats->discriminationindex = 100*$stats->covariance
/ sqrt($stats->gradevariance * $stats->othergradevariance);
} else {
- $stats->discriminationindex = '';
+ $stats->discriminationindex = null;
}
if ($stats->covariancemax){
$stats->discriminativeefficiency = 100*$stats->covariance / $stats->covariancemax;
} else {
- $stats->discriminativeefficiency = '';
+ $stats->discriminativeefficiency = null;
}
}
if (!isset($subquestionstats[$itemid])){
$subquestionstats[$itemid] = $this->stats_init_object();
$subquestionstats[$itemid]->usedin = array();
+ $subquestionstats[$itemid]->subquestion = true;
$subquestionstats[$itemid]->differentweights = false;
$subquestionstats[$itemid]->maxgrade = $this->questions[$state->question]->maxgrade;
} else if ($subquestionstats[$itemid]->maxgrade != $this->questions[$state->question]->maxgrade){
$this->subquestions = question_load_questions(array_keys($subquestionstats));
foreach (array_keys($this->subquestions) as $qid){
$this->subquestions[$qid]->_stats = $subquestionstats[$qid];
+ $this->subquestions[$qid]->_stats->questionid = $qid;
$this->subquestions[$qid]->maxgrade = $this->subquestions[$qid]->_stats->maxgrade;
- $this->subquestions[$qid]->subquestion = true;
$this->_initial_question_walker($this->subquestions[$qid]->_stats, $this->subquestions[$qid]->_stats->maxgrade);
if ($subquestionstats[$qid]->differentweights){
notify(get_string('erroritemappearsmorethanoncewithdifferentweight', 'quiz_statistics', $this->subquestions[$qid]->name));
}
}
- foreach (array_keys($this->questions) as $qid){
+ reset($this->questions);
+ do{
+ list($qid, $question) = each($this->questions);
+ $nextquestion = current($this->questions);
+ $this->questions[$qid]->_stats->questionid = $qid;
$this->_initial_question_walker($this->questions[$qid]->_stats, $this->questions[$qid]->maxgrade);
- $this->questions[$qid]->subquestion = false;
- }
+ if ($question->qtype == 'random'){
+ $randomselectorstring = $question->category.'/'.$question->questiontext;
+ if ($nextquestion){
+ $nextrandomselectorstring = $nextquestion->category.'/'.$nextquestion->questiontext;
+ if ($nextquestion->qtype == 'random' && $randomselectorstring == $nextrandomselectorstring){
+ continue;//next loop iteration
+ }
+ }
+ if (isset($this->randomselectors[$randomselectorstring])){
+ $question->_stats->subquestions = join($this->randomselectors[$randomselectorstring], ',');
+ }
+ }
+ } while ($nextquestion);
//go through the records one more time
foreach ($this->states as $state){
$this->_secondary_states_walker($state, $this->questions[$state->question]->_stats);
* @author Martin Dougiamas, Jamie Pratt, Tim Hunt and others.
* @license http://www.gnu.org/copyleft/gpl.html GNU Public License
* @package quiz
- *//** */
+ **/
+define('QUIZ_REPORT_TIME_TO_CACHE_STATS', MINSECS * 15);
require_once($CFG->dirroot.'/mod/quiz/report/statistics/statistics_form.php');
require_once($CFG->dirroot.'/mod/quiz/report/statistics/statistics_table.php');
$pageoptions['id'] = $cm->id;
$pageoptions['q'] = $quiz->id;
$pageoptions['mode'] = 'statistics';
+
+ $questions = quiz_report_load_questions($quiz);
+ // Load the question type specific information
+ if (!get_question_options($questions)) {
+ print_error('cannotloadquestion', 'question');
+ }
+
$reporturl = new moodle_url($CFG->wwwroot.'/mod/quiz/report.php', $pageoptions);
$mform = new mod_quiz_report_statistics($reporturl);
if (!$groupstudents){
$nostudentsingroup = true;
}
+ } else {
+ $groupstudents = array();
}
- $questions = quiz_report_load_questions($quiz);
- // Load the question type specific information
- if (!get_question_options($questions)) {
- print_error('cannotloadquestion', 'question');
- }
$table = new quiz_report_statistics_table();
$table->is_downloading($download, get_string('reportstatistics','quiz_statistics'),
}
}
-
+ if (!$table->is_downloading()) {
+ // Print display options
+ $mform->set_data(array('useallattempts' => $useallattempts));
+ $mform->display();
+ }
// Print information on the number of existing attempts
if (!$table->is_downloading()) { //do not print notices when downloading
print_heading(get_string('quizinformation', 'quiz_statistics'));
if ($quiz->timeopen && $quiz->timeclose){
$quizinformationtable->data[] = array(get_string('duration', 'quiz_statistics'), format_time($quiz->timeclose - $quiz->timeopen));
}
- print_table($quizinformationtable);
}
- if (!$table->is_downloading()) {
- // Print display options
- $mform->set_data(array('useallattempts' => $useallattempts));
- $mform->display();
+
+ $timemodified = time() - QUIZ_REPORT_TIME_TO_CACHE_STATS;
+ $params = array('quizid'=>$quiz->id, 'groupid'=>$currentgroup, 'allattempts'=>$useallattempts, 'timemodified'=>$timemodified);
+ if (!$quizstats = $DB->get_record_select('quiz_statistics', 'quizid = :quizid AND groupid = :groupid AND allattempts = :allattempts AND timemodified > :timemodified', $params)){
+ list($s, $usingattemptsstring, $quizstats, $qstats) = $this->quiz_stats($nostudentsingroup, $quiz->id, $currentgroup, $groupstudents, $questions, $useallattempts);
+ $toinsert = (object)((array)$quizstats + $params);
+ $toinsert->timemodified = time();
+ $quizstatisticsid = $DB->insert_record('quiz_statistics', $toinsert);
+ foreach ($qstats->questions as $question){
+ $question->_stats->quizstatisticsid = $quizstatisticsid;
+ $DB->insert_record('quiz_question_statistics', $question->_stats, false, true);
+ }
+ foreach ($qstats->subquestions as $subquestion){
+ $subquestion->_stats->quizstatisticsid = $quizstatisticsid;
+ $DB->insert_record('quiz_question_statistics', $subquestion->_stats, false, true);
+ }
+ if (isset($qstats)){
+ $questions = $qstats->questions;
+ $subquestions = $qstats->subquestions;
+ } else {
+ $questions = array();
+ $subquestions = array();
+ }
+ } else {
+ if ($useallattempts){
+ $usingattemptsstring = get_string('allattempts', 'quiz_statistics');
+ $s = $quizstats->allattemptscount;
+ } else {
+ $usingattemptsstring = get_string('firstattempts', 'quiz_statistics');
+ $s = $quizstats->firstattemptscount;
+ }
+ $questionstats = $DB->get_records('quiz_question_statistics', array('quizstatisticsid'=>$quizstats->id), 'subquestion ASC');
+ $questionstats = quiz_report_index_by_keys($questionstats, array('subquestion', 'questionid'));
+ if (1 < count($questionstats)){
+ list($mainquestionstats, $subquestionstats) = $questionstats;
+ $subqstofetch = array_keys($subquestionstats);
+ $subquestions = question_load_questions($subqstofetch);
+ foreach (array_keys($subquestions) as $subqid){
+ $subquestions[$subqid]->_stats = $subquestionstats[$subqid];
+ }
+ } else {
+ $mainquestionstats = $questionstats[0];
+ $subquestions = array();
+ }
+ foreach (array_keys($questions) as $qid){
+ $questions[$qid]->_stats = $mainquestionstats[$qid];
+ }
}
- $fromqa = '{quiz_attempts} qa ';
- $whereqa = 'quiz = :quizid AND preview=0 AND timefinish !=0 ';
- $qaparams = array('quizid'=>$quiz->id);
- if (!empty($currentgroup) && $groupstudents) {
- list($grpsql, $grpparams) = $DB->get_in_or_equal(array_keys($groupstudents), SQL_PARAMS_NAMED, 'u0000');
- $whereqa .= ' AND qa.userid '.$grpsql.' ';
- $qaparams += $grpparams;
+ if (!$table->is_downloading()){
+ if ($s==0){
+ print_heading(get_string('noattempts','quiz'));
+ }
+ $format = array('firstattemptscount' => '',
+ 'allattemptscount' => '',
+ 'firstattemptsavg' => 'sumgrades_as_percentage',
+ 'allattemptsavg' => 'sumgrades_as_percentage',
+ 'median' => 'sumgrades_as_percentage',
+ 'standarddeviation' => 'sumgrades_as_percentage',
+ 'skewness' => '',
+ 'kurtosis' => '',
+ 'cic' => 'number_format',
+ 'errorratio' => 'number_format',
+ 'standarderror' => 'sumgrades_as_percentage');
+ foreach ($quizstats as $property => $value){
+ if (!isset($format[$property])){
+ continue;
+ }
+ switch ($format[$property]){
+ case 'sumgrades_as_percentage' :
+ $formattedvalue = quiz_report_scale_sumgrades_as_percentage($value, $quiz);
+ break;
+ case 'number_format' :
+ $formattedvalue = number_format($value, $quiz->decimalpoints).' %';
+ break;
+ default :
+ $formattedvalue = $value;
+ }
+ $quizinformationtable->data[] = array(get_string($property, 'quiz_statistics', $usingattemptsstring), $formattedvalue);
+ }
+ print_table($quizinformationtable);
+
}
- $sql = 'SELECT (CASE WHEN attempt=1 THEN 1 ELSE 0 END) AS isfirst, COUNT(1) AS countrecs, SUM(sumgrades) AS total ' .
- 'FROM '.$fromqa.
- 'WHERE ' .$whereqa.
- 'GROUP BY (attempt=1)';
+ if (!$table->is_downloading()){
+ print_heading(get_string('quizstructureanalysis', 'quiz_statistics'));
+ }
+ if ($s){
+ $table->setup($quiz, $cm->id, $reporturl, $s);
+
+ foreach ($questions as $question){
+ $table->add_data_keyed($table->format_row($question));
+ if (!empty($question->_stats->subquestions)){
+ $subitemstodisplay = explode(',', $question->_stats->subquestions);
+ foreach ($subitemstodisplay as $subitemid){
+ $subquestions[$subitemid]->maxgrade = $question->maxgrade;
+ $table->add_data_keyed($table->format_row($subquestions[$subitemid]));
+ }
+ }
+ }
+ $table->finish_output();
+ }
+ return true;
+ }
+
+
+ function quiz_stats($nostudentsingroup, $quizid, $currentgroup, $groupstudents, $questions, $useallattempts){
+ global $CFG, $DB;
if (!$nostudentsingroup){
//Calculating_MEAN_of_grades_for_all_attempts_by_students
//http://docs.moodle.org/en/Development:Quiz_item_analysis_calculations_in_practise#Calculating_MEAN_of_grades_for_all_attempts_by_students
+
+ list($fromqa, $whereqa, $qaparams) = quiz_report_attempts_sql($quizid, $currentgroup, $groupstudents);
+
+ $sql = 'SELECT (CASE WHEN attempt=1 THEN 1 ELSE 0 END) AS isfirst, COUNT(1) AS countrecs, SUM(sumgrades) AS total ' .
+ 'FROM '.$fromqa.
+ 'WHERE ' .$whereqa.
+ 'GROUP BY (attempt=1)';
if (!$attempttotals = $DB->get_records_sql($sql, $qaparams)){
- print_heading(get_string('noattempts','quiz'));
$s = 0;
} else {
$firstattempt = $attempttotals[1];
$usingattempts->attempts = get_string('firstattempts', 'quiz_statistics');
$usingattempts->sql = 'AND qa.attempt=1 ';
}
- $usingattempts->heading = get_string('statsfor', 'quiz_statistics', $usingattempts->attempts);
+ $usingattemptsstring = $usingattempts->attempts;
$s = $usingattempts->countrecs;
$sumgradesavg = $usingattempts->total / $usingattempts->countrecs;
}
} else {
$s = 0;
}
-
- if ($s && !$table->is_downloading()) {
- print_heading(get_string('quizoverallstatistics', 'quiz_statistics'));
- $quizoverallstatistics = new object();
- $quizoverallstatistics->align = array('center', 'center');
- $quizoverallstatistics->width = '60%';
- $quizoverallstatistics->class = 'generaltable titlesleft';
- $quizoverallstatistics->data = array();
- $quizoverallstatistics->data[] = array(get_string('nooffirstattempts', 'quiz_statistics'), $firstattempt->countrecs);
- $quizoverallstatistics->data[] = array(get_string('noofallattempts', 'quiz_statistics'), $allattempts->countrecs);
- $quizoverallstatistics->data[] = array(get_string('firstattemptsavg', 'quiz_statistics'), quiz_report_scale_sumgrades_as_percentage($firstattempt->total / $firstattempt->countrecs, $quiz));
- $quizoverallstatistics->data[] = array(get_string('allattemptsavg', 'quiz_statistics'), quiz_report_scale_sumgrades_as_percentage($allattempts->total / $allattempts->countrecs, $quiz));
- print_table($quizoverallstatistics);
+ $quizstats = new object();
+ if ($s == 0){
+ $quizstats->firstattemptscount = 0;
+ $quizstats->allattemptscount = 0;
+ } else {
+ $quizstats->firstattemptscount = $firstattempt->countrecs;
+ $quizstats->allattemptscount = $allattempts->countrecs;
+ $quizstats->firstattemptsavg = $firstattempt->total / $firstattempt->countrecs;
+ $quizstats->allattemptsavg = $allattempts->total / $allattempts->countrecs;
}
- $quizattsstatistics = new object();
- $quizattsstatistics->align = array('center', 'center');
- $quizattsstatistics->width = '60%';
- $quizattsstatistics->class = 'generaltable titlesleft';
- $quizattsstatistics->data = array();
+ //recalculate sql again this time possibly including test for first attempt.
+ list($fromqa, $whereqa, $qaparams) = quiz_report_attempts_sql($quizid, $currentgroup, $groupstudents, $useallattempts);
+
//get the median
- if ($s && !$table->is_downloading()) {
+ if ($s) {
- print_heading($usingattempts->heading);
if (($s%2)==0){
//even number of attempts
$limitoffset = ($s/2) - 1;
$limit = 2;
} else {
- $limitoffset = (floor($s/2)) - 1;
+ $limitoffset = (floor($s/2)) + 1;
$limit = 1;
}
$sql = 'SELECT id, sumgrades ' .
'FROM ' .$fromqa.
'WHERE ' .$whereqa.
- $usingattempts->sql.
'ORDER BY sumgrades';
if (!$mediangrades = $DB->get_records_sql_menu($sql, $qaparams, $limitoffset, $limit)){
print_error('errormedian', 'quiz_statistics');
}
if (count($mediangrades)==1){
- $median = array_shift($mediangrades);
+ $quizstats->median = array_shift($mediangrades);
} else {
$median = array_shift($mediangrades);
$median += array_shift($mediangrades);
- $median = $median /2;
+ $quizstats->median = $median /2;
}
if ($s>1){
- $quizattsstatistics->data[] = array(get_string('median', 'quiz_statistics'), quiz_report_scale_sumgrades_as_percentage($median, $quiz));
//fetch sum of squared, cubed and power 4d
//differences between grades and mean grade
$mean = $usingattempts->total / $s;
"SUM(POWER((qa.sumgrades - :mean2),3)) AS power3, ".
"SUM(POWER((qa.sumgrades - :mean3),4)) AS power4 ".
'FROM ' .$fromqa.
- 'WHERE ' .$whereqa.
- $usingattempts->sql;
+ 'WHERE ' .$whereqa;
$params = array('mean1' => $mean, 'mean2' => $mean, 'mean3' => $mean)+$qaparams;
if (!$powers = $DB->get_record_sql($sql, $params)){
print_error('errorpowers', 'quiz_statistics');
//Standard_Deviation
//see http://docs.moodle.org/en/Development:Quiz_item_analysis_calculations_in_practise#Standard_Deviation
- $sd = sqrt($powers->power2 / ($s -1));
- $quizattsstatistics->data[] = array(get_string('standarddeviation', 'quiz_statistics'), quiz_report_scale_sumgrades_as_percentage($sd, $quiz));
+ $quizstats->standarddeviation = sqrt($powers->power2 / ($s -1));
+
//Skewness_and_Kurtosis
$k2= $s*$m2/($s-1);
$k3= $s*$s*$m3/(($s-1)*($s-2));
- $skewness = $k3 / (pow($k2, 2/3));
- $quizattsstatistics->data[] = array(get_string('skewness', 'quiz_statistics'), $skewness);
+ $quizstats->skewness = $k3 / (pow($k2, 2/3));
}
if ($s>3){
$k4= (($s*$s*$s)/(($s-1)*($s-2)*($s-3)))*((($s+1)*$m4)-(3*($s-1)*$m2*$m2));
- $kurtosis = $k4 / ($k2*$k2);
-
- $quizattsstatistics->data[] = array(get_string('kurtosis', 'quiz_statistics'), $kurtosis);
+ $quizstats->kurtosis = $k4 / ($k2*$k2);
}
}
}
if ($s){
require_once("$CFG->dirroot/mod/quiz/report/statistics/qstats.php");
$qstats = new qstats($questions, $s, $sumgradesavg);
- $qstats->get_records($fromqa, $whereqa, $usingattempts->sql, $qaparams);
+ $qstats->get_records($quizid, $currentgroup, $groupstudents, $useallattempts);
set_time_limit(0);
$qstats->process_states();
+ } else {
+ $qstats = false;
}
- if (!$table->is_downloading()){
- if ($s>1){
- $p = count($questions);//no of positions
- if ($p > 1){
- $cic = (100 * $p / ($p -1)) * (1 - ($qstats->sum_of_grade_variance())/$k2);
- $quizattsstatistics->data[] = array(get_string('cic', 'quiz_statistics'), number_format($cic, $quiz->decimalpoints).' %');
- $errorratio = 100 * sqrt(1-($cic/100));
- $quizattsstatistics->data[] = array(get_string('errorratio', 'quiz_statistics'), number_format($errorratio, $quiz->decimalpoints).' %');
- $standarderror = ($errorratio * $sd / 100);
- $quizattsstatistics->data[] = array(get_string('standarderror', 'quiz_statistics'),
- quiz_report_scale_sumgrades_as_percentage($standarderror, $quiz));
- }
- }
- if ($quizattsstatistics->data){
- print_table($quizattsstatistics);
- }
- }
- if (!$table->is_downloading()){
- print_heading(get_string('quizstructureanalysis', 'quiz_statistics'));
- }
- $table->setup($quiz, $cm->id, $reporturl, $s);
- if (isset($qstats)){
- while ($question = array_shift($qstats->questions)){
- $table->add_data_keyed($table->format_row($question));
- if ($question->qtype == 'random'){
- $randomselectorstring = $question->category.'/'.$question->questiontext;
- if ($qstats->questions){
- $nextquestion = current($qstats->questions);
- $nextrandomselectorstring = $nextquestion->category.'/'.$nextquestion->questiontext;
- if ($nextquestion->qtype == 'random' && $randomselectorstring == $nextrandomselectorstring){
- continue;//next loop iteration
- }
- }
- if (isset($qstats->randomselectors[$randomselectorstring])){
- foreach ($qstats->randomselectors[$randomselectorstring] as $itemid){
- $table->add_data_keyed($table->format_row($qstats->subquestions[$itemid]));
- }
- }
- }
+ if ($s>1){
+ $p = count($qstats->questions);//no of positions
+ if ($p > 1){
+ $quizstats->cic = (100 * $p / ($p -1)) * (1 - ($qstats->sum_of_grade_variance())/$k2);
+ $quizstats->errorratio = 100 * sqrt(1-($quizstats->cic/100));
+ $quizstats->standarderror = ($quizstats->errorratio * $quizstats->standarddeviation / 100);
+
}
}
- $table->finish_output();
- return true;
+ return array($s, $usingattemptsstring, $quizstats, $qstats);
}
}
-
-
+function quiz_report_attempts_sql($quizid, $currentgroup, $groupstudents, $allattempts = true){
+ $fromqa = '{quiz_attempts} qa ';
+ $whereqa = 'quiz = :quizid AND preview=0 AND timefinish !=0 ';
+ $qaparams = array('quizid'=>$quizid);
+ if (!empty($currentgroup) && $groupstudents) {
+ list($grpsql, $grpparams) = $DB->get_in_or_equal(array_keys($groupstudents), SQL_PARAMS_NAMED, 'u0000');
+ $whereqa .= 'AND qa.userid '.$grpsql.' ';
+ $qaparams += $grpparams;
+ }
+ if (!$allattempts){
+ $whereqa .= 'AND qa.attempt=1 ';
+ }
+ return array($fromqa, $whereqa, $qaparams);
+}
?>
projects / moodle.git / commitdiff