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MDL-41725 move db tables from quiz stats report

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to question bank

- move cron to clean up old cache records move code and
rename classes
- further review of the quiz reports statistics code
- starting to separate calculations of quiz stats, question stats and
response analysis
- introduce hashcode db field for cached stats convert
- code to use qubaids hashcode for caches

We just drop the old tables (including previous upgrade steps) and
re-create the new ones, because these tables just cache calculated
statistics. No important data is stored in them.
This commit is contained in:
Jamie Pratt 2013-09-11 18:54:22 +07:00
parent 7f3836d15a
commit e68e4ccfdc
19 changed files with 936 additions and 805 deletions
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42
lib/db/install.xml
View File

@ -1484,6 +1484,46 @@
<INDEX NAME="attemptid-questionid" UNIQUE="true" FIELDS="attemptid, questionid"/>
</INDEXES>
</TABLE>
<TABLE NAME="question_statistics" COMMENT="Statistics for individual questions used in an activity.">
<FIELDS>
<FIELD NAME="id" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="true"/>
<FIELD NAME="hashcode" TYPE="char" LENGTH="40" NOTNULL="true" SEQUENCE="false" COMMENT="sha1 hash of serialized qubaids_condition class. Unique for every combination of class name and property."/>
<FIELD NAME="timemodified" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false"/>
<FIELD NAME="questionid" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false"/>
<FIELD NAME="slot" TYPE="int" LENGTH="10" NOTNULL="false" SEQUENCE="false" COMMENT="The position in the quiz where this question appears"/>
<FIELD NAME="subquestion" TYPE="int" LENGTH="4" NOTNULL="true" SEQUENCE="false"/>
<FIELD NAME="s" TYPE="int" LENGTH="10" NOTNULL="true" DEFAULT="0" SEQUENCE="false"/>
<FIELD NAME="effectiveweight" TYPE="number" LENGTH="15" NOTNULL="false" SEQUENCE="false" DECIMALS="5"/>
<FIELD NAME="negcovar" TYPE="int" LENGTH="2" NOTNULL="true" DEFAULT="0" SEQUENCE="false"/>
<FIELD NAME="discriminationindex" TYPE="number" LENGTH="15" NOTNULL="false" SEQUENCE="false" DECIMALS="5"/>
<FIELD NAME="discriminativeefficiency" TYPE="number" LENGTH="15" NOTNULL="false" SEQUENCE="false" DECIMALS="5"/>
<FIELD NAME="sd" TYPE="number" LENGTH="15" NOTNULL="false" SEQUENCE="false" DECIMALS="10"/>
<FIELD NAME="facility" TYPE="number" LENGTH="15" NOTNULL="false" SEQUENCE="false" DECIMALS="10"/>
<FIELD NAME="subquestions" TYPE="text" NOTNULL="false" SEQUENCE="false"/>
<FIELD NAME="maxmark" TYPE="number" LENGTH="12" NOTNULL="false" SEQUENCE="false" DECIMALS="7"/>
<FIELD NAME="positions" TYPE="text" NOTNULL="false" SEQUENCE="false" COMMENT="positions in which this item appears. Only used for random questions."/>
<FIELD NAME="randomguessscore" TYPE="number" LENGTH="12" NOTNULL="false" SEQUENCE="false" DECIMALS="7" COMMENT="An estimate of the score a student would get by guessing randomly."/>
</FIELDS>
<KEYS>
<KEY NAME="primary" TYPE="primary" FIELDS="id"/>
</KEYS>
</TABLE>
<TABLE NAME="question_response_analysis" COMMENT="Analysis of student responses given to questions.">
<FIELDS>
<FIELD NAME="id" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="true"/>
<FIELD NAME="hashcode" TYPE="char" LENGTH="40" NOTNULL="true" SEQUENCE="false" COMMENT="sha1 hash of serialized qubaids_condition class. Unique for every combination of class name and property."/>
<FIELD NAME="timemodified" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false"/>
<FIELD NAME="questionid" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false"/>
<FIELD NAME="subqid" TYPE="char" LENGTH="100" NOTNULL="true" SEQUENCE="false"/>
<FIELD NAME="aid" TYPE="char" LENGTH="100" NOTNULL="false" SEQUENCE="false"/>
<FIELD NAME="response" TYPE="text" LENGTH="big" NOTNULL="false" SEQUENCE="false"/>
<FIELD NAME="rcount" TYPE="int" LENGTH="10" NOTNULL="false" SEQUENCE="false"/>
<FIELD NAME="credit" TYPE="number" LENGTH="15" NOTNULL="true" SEQUENCE="false" DECIMALS="5"/>
</FIELDS>
<KEYS>
<KEY NAME="primary" TYPE="primary" FIELDS="id"/>
</KEYS>
</TABLE>
<TABLE NAME="mnet_application" COMMENT="Information about applications on remote hosts">
<FIELDS>
<FIELD NAME="id" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="true"/>
@ -3013,4 +3053,4 @@
</KEYS>
</TABLE>
</TABLES>
</XMLDB>
</XMLDB>

58
lib/db/upgrade.php
View File

@ -2450,5 +2450,63 @@ function xmldb_main_upgrade($oldversion) {
upgrade_main_savepoint(true, 2013091300.01);
}
if ($oldversion < 2013092000.01) {
// Define table question_statistics to be created.
$table = new xmldb_table('question_statistics');
// Adding fields to table question_statistics.
$table->add_field('id', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, XMLDB_SEQUENCE, null);
$table->add_field('hashcode', XMLDB_TYPE_CHAR, '40', null, XMLDB_NOTNULL, null, null);
$table->add_field('timemodified', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, null);
$table->add_field('questionid', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, null);
$table->add_field('slot', XMLDB_TYPE_INTEGER, '10', null, null, null, null);
$table->add_field('subquestion', XMLDB_TYPE_INTEGER, '4', null, XMLDB_NOTNULL, null, null);
$table->add_field('s', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, '0');
$table->add_field('effectiveweight', XMLDB_TYPE_NUMBER, '15, 5', null, null, null, null);
$table->add_field('negcovar', XMLDB_TYPE_INTEGER, '2', null, XMLDB_NOTNULL, null, '0');
$table->add_field('discriminationindex', XMLDB_TYPE_NUMBER, '15, 5', null, null, null, null);
$table->add_field('discriminativeefficiency', XMLDB_TYPE_NUMBER, '15, 5', null, null, null, null);
$table->add_field('sd', XMLDB_TYPE_NUMBER, '15, 10', null, null, null, null);
$table->add_field('facility', XMLDB_TYPE_NUMBER, '15, 10', null, null, null, null);
$table->add_field('subquestions', XMLDB_TYPE_TEXT, null, null, null, null, null);
$table->add_field('maxmark', XMLDB_TYPE_NUMBER, '12, 7', null, null, null, null);
$table->add_field('positions', XMLDB_TYPE_TEXT, null, null, null, null, null);
$table->add_field('randomguessscore', XMLDB_TYPE_NUMBER, '12, 7', null, null, null, null);
// Adding keys to table question_statistics.
$table->add_key('primary', XMLDB_KEY_PRIMARY, array('id'));
// Conditionally launch create table for question_statistics.
if (!$dbman->table_exists($table)) {
$dbman->create_table($table);
}
// Define table question_response_analysis to be created.
$table = new xmldb_table('question_response_analysis');
// Adding fields to table question_response_analysis.
$table->add_field('id', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, XMLDB_SEQUENCE, null);
$table->add_field('hashcode', XMLDB_TYPE_CHAR, '40', null, XMLDB_NOTNULL, null, null);
$table->add_field('timemodified', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, null);
$table->add_field('questionid', XMLDB_TYPE_INTEGER, '10', null, XMLDB_NOTNULL, null, null);
$table->add_field('subqid', XMLDB_TYPE_CHAR, '100', null, XMLDB_NOTNULL, null, null);
$table->add_field('aid', XMLDB_TYPE_CHAR, '100', null, null, null, null);
$table->add_field('response', XMLDB_TYPE_TEXT, null, null, null, null, null);
$table->add_field('rcount', XMLDB_TYPE_INTEGER, '10', null, null, null, null);
$table->add_field('credit', XMLDB_TYPE_NUMBER, '15, 5', null, XMLDB_NOTNULL, null, null);
// Adding keys to table question_response_analysis.
$table->add_key('primary', XMLDB_KEY_PRIMARY, array('id'));
// Conditionally launch create table for question_response_analysis.
if (!$dbman->table_exists($table)) {
$dbman->create_table($table);
}
// Main savepoint reached.
upgrade_main_savepoint(true, 2013092000.01);
}
return true;
}

43
mod/quiz/report/statistics/db/install.xml
View File

@ -1,5 +1,5 @@
<?xml version="1.0" encoding="UTF-8" ?>
<XMLDB PATH="mod/quiz/report/statistics/db" VERSION="20120122" COMMENT="XMLDB file for Moodle mod/quiz/report/statistics"
<XMLDB PATH="mod/quiz/report/statistics/db" VERSION="20130920" COMMENT="XMLDB file for Moodle mod/quiz/report/statistics"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespaceSchemaLocation="../../../../../lib/xmldb/xmldb.xsd"
>
@ -7,8 +7,7 @@
<TABLE NAME="quiz_statistics" COMMENT="table to cache results from analysis done in statistics report for quizzes.">
<FIELDS>
<FIELD NAME="id" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="true"/>
<FIELD NAME="quizid" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false"/>
<FIELD NAME="groupid" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false"/>
<FIELD NAME="hashcode" TYPE="char" LENGTH="40" NOTNULL="true" SEQUENCE="false" COMMENT="sha1 hash of serialized qubaids_condition class. Unique for every combination of class name and property."/>
<FIELD NAME="allattempts" TYPE="int" LENGTH="4" NOTNULL="true" SEQUENCE="false" COMMENT="bool used to indicate whether these stats are for all attempts or just for the first."/>
<FIELD NAME="timemodified" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false"/>
<FIELD NAME="firstattemptscount" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false"/>
@ -27,43 +26,5 @@
<KEY NAME="primary" TYPE="primary" FIELDS="id"/>
</KEYS>
</TABLE>
<TABLE NAME="quiz_question_statistics" COMMENT="Default comment for the table, please edit me">
<FIELDS>
<FIELD NAME="id" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="true"/>
<FIELD NAME="quizstatisticsid" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false"/>
<FIELD NAME="questionid" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false"/>
<FIELD NAME="slot" TYPE="int" LENGTH="10" NOTNULL="false" SEQUENCE="false" COMMENT="The position in the quiz where this question appears"/>
<FIELD NAME="subquestion" TYPE="int" LENGTH="4" NOTNULL="true" SEQUENCE="false"/>
<FIELD NAME="s" TYPE="int" LENGTH="10" NOTNULL="true" DEFAULT="0" SEQUENCE="false"/>
<FIELD NAME="effectiveweight" TYPE="number" LENGTH="15" NOTNULL="false" SEQUENCE="false" DECIMALS="5"/>
<FIELD NAME="negcovar" TYPE="int" LENGTH="2" NOTNULL="true" DEFAULT="0" SEQUENCE="false"/>
<FIELD NAME="discriminationindex" TYPE="number" LENGTH="15" NOTNULL="false" SEQUENCE="false" DECIMALS="5"/>
<FIELD NAME="discriminativeefficiency" TYPE="number" LENGTH="15" NOTNULL="false" SEQUENCE="false" DECIMALS="5"/>
<FIELD NAME="sd" TYPE="number" LENGTH="15" NOTNULL="false" SEQUENCE="false" DECIMALS="10"/>
<FIELD NAME="facility" TYPE="number" LENGTH="15" NOTNULL="false" SEQUENCE="false" DECIMALS="10"/>
<FIELD NAME="subquestions" TYPE="text" NOTNULL="false" SEQUENCE="false"/>
<FIELD NAME="maxmark" TYPE="number" LENGTH="12" NOTNULL="false" SEQUENCE="false" DECIMALS="7"/>
<FIELD NAME="positions" TYPE="text" NOTNULL="false" SEQUENCE="false" COMMENT="positions in which this item appears. Only used for random questions."/>
<FIELD NAME="randomguessscore" TYPE="number" LENGTH="12" NOTNULL="false" SEQUENCE="false" DECIMALS="7" COMMENT="An estimate of the score a student would get by guessing randomly."/>
</FIELDS>
<KEYS>
<KEY NAME="primary" TYPE="primary" FIELDS="id"/>
</KEYS>
</TABLE>
<TABLE NAME="quiz_question_response_stats" COMMENT="Quiz question responses.">
<FIELDS>
<FIELD NAME="id" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="true"/>
<FIELD NAME="quizstatisticsid" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false"/>
<FIELD NAME="questionid" TYPE="int" LENGTH="10" NOTNULL="true" SEQUENCE="false"/>
<FIELD NAME="subqid" TYPE="char" LENGTH="100" NOTNULL="true" SEQUENCE="false"/>
<FIELD NAME="aid" TYPE="char" LENGTH="100" NOTNULL="false" SEQUENCE="false"/>
<FIELD NAME="response" TYPE="text" LENGTH="big" NOTNULL="false" SEQUENCE="false"/>
<FIELD NAME="rcount" TYPE="int" LENGTH="10" NOTNULL="false" SEQUENCE="false"/>
<FIELD NAME="credit" TYPE="number" LENGTH="15" NOTNULL="true" SEQUENCE="false" DECIMALS="5"/>
</FIELDS>
<KEYS>
<KEY NAME="primary" TYPE="primary" FIELDS="id"/>
</KEYS>
</TABLE>
</TABLES>
</XMLDB>

68
mod/quiz/report/statistics/db/upgrade.php
View File

@ -37,43 +37,55 @@ function xmldb_quiz_statistics_upgrade($oldversion) {
// Moodle v2.2.0 release upgrade line.
// Put any upgrade step following this.
if ($oldversion < 2012061800) {
// Changing type of field subqid on table quiz_question_response_stats to char.
$table = new xmldb_table('quiz_question_response_stats');
$field = new xmldb_field('subqid', XMLDB_TYPE_CHAR, '100', null, XMLDB_NOTNULL, null, null, 'questionid');
// Launch change of type for field subqid.
$dbman->change_field_type($table, $field);
// Statistics savepoint reached.
upgrade_plugin_savepoint(true, 2012061800, 'quiz', 'statistics');
}
if ($oldversion < 2012061801) {
// Changing type of field aid on table quiz_question_response_stats to char.
$table = new xmldb_table('quiz_question_response_stats');
$field = new xmldb_field('aid', XMLDB_TYPE_CHAR, '100', null, null, null, null, 'subqid');
// Launch change of type for field aid.
$dbman->change_field_type($table, $field);
// Statistics savepoint reached.
upgrade_plugin_savepoint(true, 2012061801, 'quiz', 'statistics');
}
// Moodle v2.3.0 release upgrade line
// Put any upgrade step following this
// Moodle v2.4.0 release upgrade line
// Put any upgrade step following this
// Moodle v2.5.0 release upgrade line.
// Put any upgrade step following this.
if ($oldversion < 2013092000) {
// Define table question_statistics to be dropped.
$table = new xmldb_table('quiz_question_statistics');
// Conditionally launch drop table for question_statistics.
if ($dbman->table_exists($table)) {
$dbman->drop_table($table);
}
// Define table question_response_analysis to be dropped.
$table = new xmldb_table('quiz_question_response_stats');
// Conditionally launch drop table for question_response_analysis.
if ($dbman->table_exists($table)) {
$dbman->drop_table($table);
}
$table = new xmldb_table('quiz_statistics');
$field = new xmldb_field('quizid');
if ($dbman->field_exists($table, $field)) {
$dbman->drop_field($table, $field);
}
$field = new xmldb_field('groupid');
if ($dbman->field_exists($table, $field)) {
$dbman->drop_field($table, $field);
}
$field = new xmldb_field('hashcode', XMLDB_TYPE_CHAR, '40', null, XMLDB_NOTNULL, null, null, 'id');
if (!$dbman->field_exists($table, $field)) {
$dbman->add_field($table, $field);
}
// Main savepoint reached.
upgrade_plugin_savepoint(true, 2013092000, 'quiz', 'statistics');
}
return true;
}

20
mod/quiz/report/statistics/lib.php
View File

@ -68,24 +68,10 @@ function quiz_statistics_question_preview_pluginfile($previewcontext, $questioni
function quiz_statistics_cron() {
global $DB;
mtrace("\n Cleaning up old quiz statistics cache records...", '');
$expiretime = time() - 5*HOURSECS;
$todelete = $DB->get_records_select_menu('quiz_statistics',
'timemodified < ?', array($expiretime), '', 'id, 1');
if (!$todelete) {
return true;
}
list($todeletesql, $todeleteparams) = $DB->get_in_or_equal(array_keys($todelete));
$DB->delete_records_select('quiz_question_statistics',
'quizstatisticsid ' . $todeletesql, $todeleteparams);
$DB->delete_records_select('quiz_question_response_stats',
'quizstatisticsid ' . $todeletesql, $todeleteparams);
$DB->delete_records_select('quiz_statistics',
'id ' . $todeletesql, $todeleteparams);
$DB->delete_records_select('quiz_statistics', 'timemodified < ?', array($expiretime));
return true;
}

405
mod/quiz/report/statistics/qstats.php
View File

@ -1,405 +0,0 @@
<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* Quiz statistics report calculations class.
*
* @package quiz_statistics
* @copyright 2008 Jamie Pratt
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
defined('MOODLE_INTERNAL') || die();
/**
* This class has methods to compute the question statistics from the raw data.
*
* @copyright 2008 Jamie Pratt
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class quiz_statistics_question_stats {
public $questions;
public $subquestions = array();
protected $s;
protected $summarksavg;
protected $allattempts;
/** @var mixed states from which to calculate stats - iteratable. */
protected $lateststeps;
protected $sumofmarkvariance = 0;
protected $randomselectors = array();
/**
* Constructor.
* @param $questions the questions.
* @param $s the number of attempts included in the stats.
* @param $summarksavg the average attempt summarks.
*/
public function __construct($questions, $s, $summarksavg) {
$this->s = $s;
$this->summarksavg = $summarksavg;
foreach ($questions as $slot => $question) {
$question->_stats = $this->make_blank_question_stats();
$question->_stats->questionid = $question->id;
$question->_stats->slot = $slot;
}
$this->questions = $questions;
}
/**
* @return object ready to hold all the question statistics.
*/
protected function make_blank_question_stats() {
$stats = new stdClass();
$stats->slot = null;
$stats->s = 0;
$stats->totalmarks = 0;
$stats->totalothermarks = 0;
$stats->markvariancesum = 0;
$stats->othermarkvariancesum = 0;
$stats->covariancesum = 0;
$stats->covariancemaxsum = 0;
$stats->subquestion = false;
$stats->subquestions = '';
$stats->covariancewithoverallmarksum = 0;
$stats->randomguessscore = null;
$stats->markarray = array();
$stats->othermarksarray = array();
return $stats;
}
/**
* Load the data that will be needed to perform the calculations.
*
* @param int $quizid the quiz id.
* @param int $currentgroup the current group. 0 for none.
* @param array $groupstudents students in this group.
* @param bool $allattempts use all attempts, or just first attempts.
*/
public function load_step_data($quizid, $currentgroup, $groupstudents, $allattempts) {
global $DB;
$this->allattempts = $allattempts;
list($qsql, $qparams) = $DB->get_in_or_equal(array_keys($this->questions),
SQL_PARAMS_NAMED, 'q');
list($fromqa, $whereqa, $qaparams) = quiz_statistics_attempts_sql(
$quizid, $currentgroup, $groupstudents, $allattempts, false);
$this->lateststeps = $DB->get_records_sql("
SELECT
qas.id,
quiza.sumgrades,
qa.questionid,
qa.slot,
qa.maxmark,
qas.fraction * qa.maxmark as mark
FROM $fromqa
JOIN {question_attempts} qa ON qa.questionusageid = quiza.uniqueid
JOIN (
SELECT questionattemptid, MAX(id) AS latestid
FROM {question_attempt_steps}
GROUP BY questionattemptid
) lateststepid ON lateststepid.questionattemptid = qa.id
JOIN {question_attempt_steps} qas ON qas.id = lateststepid.latestid
WHERE
qa.slot $qsql AND
$whereqa", $qparams + $qaparams);
}
public function compute_statistics() {
set_time_limit(0);
$subquestionstats = array();
// Compute the statistics of position, and for random questions, work
// out which questions appear in which positions.
foreach ($this->lateststeps as $step) {
$this->initial_steps_walker($step, $this->questions[$step->slot]->_stats);
// If this is a random question what is the real item being used?
if ($step->questionid != $this->questions[$step->slot]->id) {
if (!isset($subquestionstats[$step->questionid])) {
$subquestionstats[$step->questionid] = $this->make_blank_question_stats();
$subquestionstats[$step->questionid]->questionid = $step->questionid;
$subquestionstats[$step->questionid]->allattempts = $this->allattempts;
$subquestionstats[$step->questionid]->usedin = array();
$subquestionstats[$step->questionid]->subquestion = true;
$subquestionstats[$step->questionid]->differentweights = false;
$subquestionstats[$step->questionid]->maxmark = $step->maxmark;
} else if ($subquestionstats[$step->questionid]->maxmark != $step->maxmark) {
$subquestionstats[$step->questionid]->differentweights = true;
}
$this->initial_steps_walker($step,
$subquestionstats[$step->questionid], false);
$number = $this->questions[$step->slot]->number;
$subquestionstats[$step->questionid]->usedin[$number] = $number;
$randomselectorstring = $this->questions[$step->slot]->category .
'/' . $this->questions[$step->slot]->questiontext;
if (!isset($this->randomselectors[$randomselectorstring])) {
$this->randomselectors[$randomselectorstring] = array();
}
$this->randomselectors[$randomselectorstring][$step->questionid] =
$step->questionid;
}
}
foreach ($this->randomselectors as $key => $notused) {
ksort($this->randomselectors[$key]);
}
// Compute the statistics of question id, if we need any.
$this->subquestions = question_load_questions(array_keys($subquestionstats));
foreach ($this->subquestions as $qid => $subquestion) {
$subquestion->_stats = $subquestionstats[$qid];
$subquestion->maxmark = $subquestion->_stats->maxmark;
$subquestion->_stats->randomguessscore = $this->get_random_guess_score($subquestion);
$this->initial_question_walker($subquestion->_stats);
if ($subquestionstats[$qid]->differentweights) {
// TODO output here really sucks, but throwing is too severe.
global $OUTPUT;
echo $OUTPUT->notification(
get_string('erroritemappearsmorethanoncewithdifferentweight',
'quiz_statistics', $this->subquestions[$qid]->name));
}
if ($subquestion->_stats->usedin) {
sort($subquestion->_stats->usedin, SORT_NUMERIC);
$subquestion->_stats->positions = implode(',', $subquestion->_stats->usedin);
} else {
$subquestion->_stats->positions = '';
}
}
// Finish computing the averages, and put the subquestion data into the
// corresponding questions.
// This cannot be a foreach loop because we need to have both
// $question and $nextquestion available, but apart from that it is
// foreach ($this->questions as $qid => $question).
reset($this->questions);
while (list($slot, $question) = each($this->questions)) {
$nextquestion = current($this->questions);
$question->_stats->allattempts = $this->allattempts;
$question->_stats->positions = $question->number;
$question->_stats->maxmark = $question->maxmark;
$question->_stats->randomguessscore = $this->get_random_guess_score($question);
$this->initial_question_walker($question->_stats);
if ($question->qtype == 'random') {
$randomselectorstring = $question->category.'/'.$question->questiontext;
if ($nextquestion && $nextquestion->qtype == 'random') {
$nextrandomselectorstring = $nextquestion->category . '/' .
$nextquestion->questiontext;
if ($randomselectorstring == $nextrandomselectorstring) {
continue; // Next loop iteration.
}
}
if (isset($this->randomselectors[$randomselectorstring])) {
$question->_stats->subquestions = implode(',',
$this->randomselectors[$randomselectorstring]);
}
}
}
// Go through the records one more time.
foreach ($this->lateststeps as $step) {
$this->secondary_steps_walker($step,
$this->questions[$step->slot]->_stats);
if ($this->questions[$step->slot]->qtype == 'random') {
$this->secondary_steps_walker($step,
$this->subquestions[$step->questionid]->_stats);
}
}
$sumofcovariancewithoverallmark = 0;
foreach ($this->questions as $slot => $question) {
$this->secondary_question_walker($question->_stats);
$this->sumofmarkvariance += $question->_stats->markvariance;
if ($question->_stats->covariancewithoverallmark >= 0) {
$sumofcovariancewithoverallmark +=
sqrt($question->_stats->covariancewithoverallmark);
$question->_stats->negcovar = 0;
} else {
$question->_stats->negcovar = 1;
}
}
foreach ($this->subquestions as $subquestion) {
$this->secondary_question_walker($subquestion->_stats);
}
foreach ($this->questions as $question) {
if ($sumofcovariancewithoverallmark) {
if ($question->_stats->negcovar) {
$question->_stats->effectiveweight = null;
} else {
$question->_stats->effectiveweight = 100 *
sqrt($question->_stats->covariancewithoverallmark) /
$sumofcovariancewithoverallmark;
}
} else {
$question->_stats->effectiveweight = null;
}
}
}
/**
* Update $stats->totalmarks, $stats->markarray, $stats->totalothermarks
* and $stats->othermarksarray to include another state.
*
* @param object $step the state to add to the statistics.
* @param object $stats the question statistics we are accumulating.
* @param bool $positionstat whether this is a statistic of position of question.
*/
protected function initial_steps_walker($step, $stats, $positionstat = true) {
$stats->s++;
$stats->totalmarks += $step->mark;
$stats->markarray[] = $step->mark;
if ($positionstat) {
$stats->totalothermarks += $step->sumgrades - $step->mark;
$stats->othermarksarray[] = $step->sumgrades - $step->mark;
} else {
$stats->totalothermarks += $step->sumgrades;
$stats->othermarksarray[] = $step->sumgrades;
}
}
/**
* Perform some computations on the per-question statistics calculations after
* we have been through all the states.
*
* @param object $stats quetsion stats to update.
*/
protected function initial_question_walker($stats) {
$stats->markaverage = $stats->totalmarks / $stats->s;
if ($stats->maxmark != 0) {
$stats->facility = $stats->markaverage / $stats->maxmark;
} else {
$stats->facility = null;
}
$stats->othermarkaverage = $stats->totalothermarks / $stats->s;
sort($stats->markarray, SORT_NUMERIC);
sort($stats->othermarksarray, SORT_NUMERIC);
}
/**
* Now we know the averages, accumulate the date needed to compute the higher
* moments of the question scores.
*
* @param object $step the state to add to the statistics.
* @param object $stats the question statistics we are accumulating.
* @param bool $positionstat whether this is a statistic of position of question.
*/
protected function secondary_steps_walker($step, $stats) {
$markdifference = $step->mark - $stats->markaverage;
if ($stats->subquestion) {
$othermarkdifference = $step->sumgrades - $stats->othermarkaverage;
} else {
$othermarkdifference = $step->sumgrades - $step->mark -
$stats->othermarkaverage;
}
$overallmarkdifference = $step->sumgrades - $this->summarksavg;
$sortedmarkdifference = array_shift($stats->markarray) - $stats->markaverage;
$sortedothermarkdifference = array_shift($stats->othermarksarray) -
$stats->othermarkaverage;
$stats->markvariancesum += pow($markdifference, 2);
$stats->othermarkvariancesum += pow($othermarkdifference, 2);
$stats->covariancesum += $markdifference * $othermarkdifference;
$stats->covariancemaxsum += $sortedmarkdifference * $sortedothermarkdifference;
$stats->covariancewithoverallmarksum += $markdifference * $overallmarkdifference;
}
/**
* Perform more per-question statistics calculations.
*
* @param object $stats quetsion stats to update.
*/
protected function secondary_question_walker($stats) {
if ($stats->s > 1) {
$stats->markvariance = $stats->markvariancesum / ($stats->s - 1);
$stats->othermarkvariance = $stats->othermarkvariancesum / ($stats->s - 1);
$stats->covariance = $stats->covariancesum / ($stats->s - 1);
$stats->covariancemax = $stats->covariancemaxsum / ($stats->s - 1);
$stats->covariancewithoverallmark = $stats->covariancewithoverallmarksum /
($stats->s - 1);
$stats->sd = sqrt($stats->markvariancesum / ($stats->s - 1));
} else {
$stats->markvariance = null;
$stats->othermarkvariance = null;
$stats->covariance = null;
$stats->covariancemax = null;
$stats->covariancewithoverallmark = null;
$stats->sd = null;
}
if ($stats->markvariance * $stats->othermarkvariance) {
$stats->discriminationindex = 100 * $stats->covariance /
sqrt($stats->markvariance * $stats->othermarkvariance);
} else {
$stats->discriminationindex = null;
}
if ($stats->covariancemax) {
$stats->discriminativeefficiency = 100 * $stats->covariance /
$stats->covariancemax;
} else {
$stats->discriminativeefficiency = null;
}
}
/**
* @param object $questiondata
* @return number the random guess score for this question.
*/
protected function get_random_guess_score($questiondata) {
return question_bank::get_qtype(
$questiondata->qtype, false)->get_random_guess_score($questiondata);
}
/**
* Used when computing CIC.
* @return number
*/
public function get_sum_of_mark_variance() {
return $this->sumofmarkvariance;
}
}

341
mod/quiz/report/statistics/report.php
View File

@ -28,9 +28,9 @@ defined('MOODLE_INTERNAL') || die();
require_once($CFG->dirroot . '/mod/quiz/report/statistics/statistics_form.php');
require_once($CFG->dirroot . '/mod/quiz/report/statistics/statistics_table.php');
require_once($CFG->dirroot . '/mod/quiz/report/statistics/statistics_question_table.php');
require_once($CFG->dirroot . '/mod/quiz/report/statistics/qstats.php');
require_once($CFG->dirroot . '/mod/quiz/report/statistics/responseanalysis.php');
require_once($CFG->dirroot . '/question/engine/statistics.php');
require_once($CFG->dirroot . '/question/engine/responseanalysis.php');
require_once($CFG->dirroot . '/mod/quiz/report/statistics/statisticslib.php');
/**
* The quiz statistics report provides summary information about each question in
@ -104,9 +104,12 @@ class quiz_statistics_report extends quiz_default_report {
}
}
$qubaids = quiz_statistics_qubaids_condition($quiz->id, $currentgroup, $groupstudents, $useallattempts);
// If recalculate was requested, handle that.
if ($recalculate && confirm_sesskey()) {
$this->clear_cached_data($quiz->id, $currentgroup, $useallattempts);
$this->clear_cached_data($qubaids);
redirect($reporturl);
}
@ -164,21 +167,21 @@ class quiz_statistics_report extends quiz_default_report {
if ($s) {
$this->output_quiz_structure_analysis_table($s, $questions, $subquestions);
if ($this->table->is_downloading() == 'xhtml') {
$this->output_statistics_graph($quizstats->id, $s);
if ($this->table->is_downloading() == 'xhtml' && $s != 0) {
$this->output_statistics_graph($quiz->id, $currentgroup, $useallattempts);
}
foreach ($questions as $question) {
if (question_bank::get_qtype(
$question->qtype, false)->can_analyse_responses()) {
$this->output_individual_question_response_analysis(
$question, $reporturl, $quizstats);
$question, $reporturl, $qubaids);
} else if (!empty($question->_stats->subquestions)) {
$subitemstodisplay = explode(',', $question->_stats->subquestions);
foreach ($subitemstodisplay as $subitemid) {
$this->output_individual_question_response_analysis(
$subquestions[$subitemid], $reporturl, $quizstats);
$subquestions[$subitemid], $reporturl, $qubaids);
}
}
}
@ -194,7 +197,7 @@ class quiz_statistics_report extends quiz_default_report {
$this->output_individual_question_data($quiz, $questions[$slot]);
$this->output_individual_question_response_analysis(
$questions[$slot], $reporturl, $quizstats);
$questions[$slot], $reporturl, $qubaids);
// Back to overview link.
echo $OUTPUT->box('<a href="' . $reporturl->out() . '">' .
@ -209,7 +212,7 @@ class quiz_statistics_report extends quiz_default_report {
$this->output_individual_question_data($quiz, $subquestions[$qid]);
$this->output_individual_question_response_analysis(
$subquestions[$qid], $reporturl, $quizstats);
$subquestions[$qid], $reporturl, $qubaids);
// Back to overview link.
echo $OUTPUT->box('<a href="' . $reporturl->out() . '">' .
@ -232,7 +235,7 @@ class quiz_statistics_report extends quiz_default_report {
if ($s) {
echo $OUTPUT->heading(get_string('quizstructureanalysis', 'quiz_statistics'));
$this->output_quiz_structure_analysis_table($s, $questions, $subquestions);
$this->output_statistics_graph($quizstats->id, $s);
$this->output_statistics_graph($quiz->id, $currentgroup, $useallattempts);
}
}
@ -323,12 +326,12 @@ class quiz_statistics_report extends quiz_default_report {
/**
* Display the response analysis for a question.
* @param object $question the question to report on.
* @param object $question the question to report on.
* @param moodle_url $reporturl the URL to resisplay this report.
* @param object $quizstats Holds the quiz statistics.
* @param qubaid_condition $qubaids
*/
protected function output_individual_question_response_analysis($question,
$reporturl, $quizstats) {
$reporturl, $qubaids) {
global $OUTPUT;
if (!question_bank::get_qtype($question->qtype, false)->can_analyse_responses()) {
@ -361,8 +364,8 @@ class quiz_statistics_report extends quiz_default_report {
}
}
$responesstats = new quiz_statistics_response_analyser($question);
$responesstats->load_cached($quizstats->id);
$responesstats = new question_response_analyser($question);
$responesstats->load_cached($qubaids);
$qtable->question_setup($reporturl, $question, $responesstats);
if ($this->table->is_downloading()) {
@ -549,18 +552,16 @@ class quiz_statistics_report extends quiz_default_report {
/**
* Output the HTML needed to show the statistics graph.
* @param int $quizstatsid the id of the statistics to show in the graph.
* @param $quizid
* @param $currentgroup
* @param $useallattempts
*/
protected function output_statistics_graph($quizstatsid, $s) {
protected function output_statistics_graph($quizid, $currentgroup, $useallattempts) {
global $PAGE;
if ($s == 0) {
return;
}
$output = $PAGE->get_renderer('mod_quiz');
$imageurl = new moodle_url('/mod/quiz/report/statistics/statistics_graph.php',
array('id' => $quizstatsid));
compact('quizid', 'currentgroup', 'useallattempts'));
$graphname = get_string('statisticsreportgraph', 'quiz_statistics');
echo $output->graph($imageurl, $graphname);
}
@ -568,53 +569,39 @@ class quiz_statistics_report extends quiz_default_report {
/**
* Return the stats data for when there are no stats to show.
*
* @param array $questions question definitions.
* @param int $firstattemptscount number of first attempts (optional).
* @param int $firstattemptscount total number of attempts (optional).
* @return array with three elements:
* @param int $allattemptscount total number of attempts (optional).
* @return array with two elements:
* - integer $s Number of attempts included in the stats (0).
* - array $quizstats The statistics for overall attempt scores.
* - array $qstats The statistics for each question.
* - object $quizstats The statistics for overall attempt scores.
*/
protected function get_emtpy_stats($questions, $firstattemptscount = 0,
$allattemptscount = 0) {
protected function get_empty_stats($firstattemptscount = 0, $allattemptscount = 0) {
$quizstats = new stdClass();
$quizstats->firstattemptscount = $firstattemptscount;
$quizstats->allattemptscount = $allattemptscount;
$qstats = new stdClass();
$qstats->questions = $questions;
$qstats->subquestions = array();
$qstats->responses = array();
return array(0, $quizstats, false);
return array(0, $quizstats);
}
/**
* Compute the quiz statistics.
*
* @param int $quizid the quiz id.
* @param int $currentgroup the current group. 0 for none.
* @param bool $nostudentsingroup true if there a no students.
* @param bool $useallattempts use all attempts, or just first attempts.
* @param array $groupstudents students in this group.
* @param array $questions question definitions.
* @return array with three elements:
* @param int $quizid the quiz id.
* @param int $currentgroup the current group. 0 for none.
* @param bool $useallattempts use all attempts, or just first attempts.
* @param array $groupstudents students in this group.
* @param int $p number of positions (slots).
* @param float $sumofmarkvariance sum of mark variance, calculated as part of question statistics
* @return array with two elements:
* - integer $s Number of attempts included in the stats.
* - array $quizstats The statistics for overall attempt scores.
* - array $qstats The statistics for each question.
* - object $quizstats The statistics for overall attempt scores.
*/
protected function compute_stats($quizid, $currentgroup, $nostudentsingroup,
$useallattempts, $groupstudents, $questions) {
protected function calculate_quiz_stats($quizid, $currentgroup, $useallattempts, $groupstudents, $p, $sumofmarkvariance) {
global $DB;
// Calculating MEAN of marks for all attempts by students
// http://docs.moodle.org/dev/Quiz_item_analysis_calculations_in_practise
// #Calculating_MEAN_of_grades_for_all_attempts_by_students.
if ($nostudentsingroup) {
return $this->get_emtpy_stats($questions);
}
list($fromqa, $whereqa, $qaparams) = quiz_statistics_attempts_sql(
$quizid, $currentgroup, $groupstudents, true);
@ -628,7 +615,7 @@ class quiz_statistics_report extends quiz_default_report {
GROUP BY CASE WHEN attempt = 1 THEN 1 ELSE 0 END", $qaparams);
if (!$attempttotals) {
return $this->get_emtpy_stats($questions);
return $this->get_empty_stats();
}
if (isset($attempttotals[1])) {
@ -660,10 +647,8 @@ class quiz_statistics_report extends quiz_default_report {
$s = $usingattempts->countrecs;
if ($s == 0) {
return $this->get_emtpy_stats($questions, $firstattempts->countrecs,
$allattempts->countrecs);
return $this->get_empty_stats($firstattempts->countrecs, $allattempts->countrecs);
}
$summarksavg = $usingattempts->total / $usingattempts->countrecs;
$quizstats = new stdClass();
$quizstats->allattempts = $useallattempts;
@ -726,113 +711,55 @@ class quiz_statistics_report extends quiz_default_report {
if ($k2) {
$quizstats->skewness = $k3 / (pow($k2, 3/2));
}
}
// Kurtosis.
if ($s > 3) {
$k4= $s*$s*((($s+1)*$m4)-(3*($s-1)*$m2*$m2))/(($s-1)*($s-2)*($s-3));
if ($k2) {
$quizstats->kurtosis = $k4 / ($k2*$k2);
// Kurtosis.
if ($s > 3) {
$k4= $s*$s*((($s+1)*$m4)-(3*($s-1)*$m2*$m2))/(($s-1)*($s-2)*($s-3));
if ($k2) {
$quizstats->kurtosis = $k4 / ($k2*$k2);
}
}
}
}
$qstats = new quiz_statistics_question_stats($questions, $s, $summarksavg);
$qstats->load_step_data($quizid, $currentgroup, $groupstudents, $useallattempts);
$qstats->compute_statistics();
if ($s > 1) {
$p = count($qstats->questions); // Number of positions.
if ($p > 1 && isset($k2)) {
$quizstats->cic = (100 * $p / ($p -1)) *
(1 - ($qstats->get_sum_of_mark_variance()) / $k2);
(1 - ($sumofmarkvariance / $k2));
$quizstats->errorratio = 100 * sqrt(1 - ($quizstats->cic / 100));
$quizstats->standarderror = $quizstats->errorratio *
$quizstats->standarddeviation / 100;
}
}
return array($s, $quizstats, $qstats);
$this->cache_stats(quiz_statistics_qubaids_condition($quizid, $currentgroup, $groupstudents, $useallattempts), $quizstats);
return array($s, $quizstats);
}
/**
* Load the cached statistics from the database.
*
* @param object $quiz the quiz settings
* @param int $currentgroup the current group. 0 for none.
* @param bool $nostudentsingroup true if there a no students.
* @param bool $useallattempts use all attempts, or just first attempts.
* @param array $groupstudents students in this group.
* @param array $questions question definitions.
* @return array with 4 elements:
* - $quizstats The statistics for overall attempt scores.
* - $questions The questions, with an additional _stats field.
* - $subquestions The subquestions, if any, with an additional _stats field.
* - $s Number of attempts included in the stats.
* If there is no cached data in the database, returns an array of four nulls.
* @param $qubaids qubaid_condition
* @return The statistics for overall attempt scores or false if not cached.
*/
protected function try_loading_cached_stats($quiz, $currentgroup,
$nostudentsingroup, $useallattempts, $groupstudents, $questions) {
protected function get_cached_quiz_stats($qubaids) {
global $DB;
$timemodified = time() - self::TIME_TO_CACHE_STATS;
$quizstats = $DB->get_record_select('quiz_statistics',
'quizid = ? AND groupid = ? AND allattempts = ? AND timemodified > ?',
array($quiz->id, $currentgroup, $useallattempts, $timemodified));
if (!$quizstats) {
// No cached data found.
return array(null, $questions, null, null);
}
if ($useallattempts) {
$s = $quizstats->allattemptscount;
} else {
$s = $quizstats->firstattemptscount;
}
$subquestions = array();
$questionstats = $DB->get_records('quiz_question_statistics',
array('quizstatisticsid' => $quizstats->id));
$subquestionstats = array();
foreach ($questionstats as $stat) {
if ($stat->slot) {
$questions[$stat->slot]->_stats = $stat;
} else {
$subquestionstats[$stat->questionid] = $stat;
}
}
if (!empty($subquestionstats)) {
$subqstofetch = array_keys($subquestionstats);
$subquestions = question_load_questions($subqstofetch);
foreach ($subquestions as $subqid => $subq) {
$subquestions[$subqid]->_stats = $subquestionstats[$subqid];
$subquestions[$subqid]->maxmark = $subq->defaultmark;
}
}
return array($quizstats, $questions, $subquestions, $s);
return $DB->get_record_select('quiz_statistics', 'hashcode = ? AND timemodified > ?',
array($qubaids->get_hash_code(), $timemodified));
}
/**
* Store the statistics in the cache tables in the database.
*
* @param object $quizid the quiz id.
* @param int $currentgroup the current group. 0 for none.
* @param bool $useallattempts use all attempts, or just first attempts.
* @param object $quizstats The statistics for overall attempt scores.
* @param array $questions The questions, with an additional _stats field.
* @param array $subquestions The subquestions, if any, with an additional _stats field.
* @param $qubaids qubaid_condition
* @param $quizstats object the quiz stats to cache
*/
protected function cache_stats($quizid, $currentgroup,
$quizstats, $questions, $subquestions) {
protected function cache_stats($qubaids, $quizstats) {
global $DB;
$toinsert = clone($quizstats);
$toinsert->quizid = $quizid;
$toinsert->groupid = $currentgroup;
$toinsert->hashcode = $qubaids->get_hash_code();
$toinsert->timemodified = time();
// Fix up some dodgy data.
@ -844,19 +771,8 @@ class quiz_statistics_report extends quiz_default_report {
}
// Store the data.
$quizstats->id = $DB->insert_record('quiz_statistics', $toinsert);
$DB->insert_record('quiz_statistics', $toinsert);
foreach ($questions as $question) {
$question->_stats->quizstatisticsid = $quizstats->id;
$DB->insert_record('quiz_question_statistics', $question->_stats, false);
}
foreach ($subquestions as $subquestion) {
$subquestion->_stats->quizstatisticsid = $quizstats->id;
$DB->insert_record('quiz_question_statistics', $subquestion->_stats, false);
}
return $quizstats->id;
}
/**
@ -878,35 +794,45 @@ class quiz_statistics_report extends quiz_default_report {
protected function get_quiz_and_questions_stats($quiz, $currentgroup,
$nostudentsingroup, $useallattempts, $groupstudents, $questions) {
list($quizstats, $questions, $subquestions, $s) =
$this->try_loading_cached_stats($quiz, $currentgroup, $nostudentsingroup,
$useallattempts, $groupstudents, $questions);
$qubaids = quiz_statistics_qubaids_condition($quiz->id, $currentgroup, $groupstudents, $useallattempts);
if (is_null($quizstats)) {
list($s, $quizstats, $qstats) = $this->compute_stats($quiz->id,
$currentgroup, $nostudentsingroup, $useallattempts, $groupstudents, $questions);
$quizstats = $this->get_cached_quiz_stats($qubaids);
$qstats = new question_statistics($questions);
if (empty($quizstats)) {
// Recalculate now.
$qstats->calculate($qubaids);
if ($nostudentsingroup) {
list($s, $quizstats) = $this->get_empty_stats();
} else {
list($s, $quizstats) = $this->calculate_quiz_stats($quiz->id, $currentgroup, $useallattempts,
$groupstudents, count($questions), $qstats->get_sum_of_mark_variance());
}
$questions = $qstats->questions;
$subquestions = $qstats->subquestions;
if ($s) {
$questions = $qstats->questions;
$subquestions = $qstats->subquestions;
$quizstatisticsid = $this->cache_stats($quiz->id, $currentgroup,
$quizstats, $questions, $subquestions);
$this->analyse_responses($quizstatisticsid, $quiz->id, $currentgroup,
$nostudentsingroup, $useallattempts, $groupstudents,
$questions, $subquestions);
$this->calculate_responses_for_all_questions_and_subquestions($qubaids, $questions, $subquestions);
}
} else {
if ($useallattempts) {
$s = $quizstats->allattemptscount;
} else {
$s = $quizstats->firstattemptscount;
}
$qstats->get_cached($qubaids);
$questions = $qstats->questions;
$subquestions = $qstats->subquestions;
}
return array($quizstats, $questions, $subquestions, $s);
}
protected function analyse_responses($quizstatisticsid, $quizid, $currentgroup,
$nostudentsingroup, $useallattempts, $groupstudents, $questions, $subquestions) {
$qubaids = quiz_statistics_qubaids_condition(
$quizid, $currentgroup, $groupstudents, $useallattempts);
protected function calculate_responses_for_all_questions_and_subquestions($qubaids, $questions, $subquestions) {
$done = array();
foreach ($questions as $question) {
@ -915,9 +841,8 @@ class quiz_statistics_report extends quiz_default_report {
}
$done[$question->id] = 1;
$responesstats = new quiz_statistics_response_analyser($question);
$responesstats->analyse($qubaids);
$responesstats->store_cached($quizstatisticsid);
$responesstats = new question_response_analyser($question);
$responesstats->calculate($qubaids);
}
foreach ($subquestions as $question) {
@ -927,9 +852,8 @@ class quiz_statistics_report extends quiz_default_report {
}
$done[$question->id] = 1;
$responesstats = new quiz_statistics_response_analyser($question);
$responesstats->analyse($qubaids);
$responesstats->store_cached($quizstatisticsid);
$responesstats = new question_response_analyser($question);
$responesstats->calculate($qubaids);
}
}
@ -957,12 +881,13 @@ class quiz_statistics_report extends quiz_default_report {
/**
* Generate the snipped of HTML that says when the stats were last caculated,
* with a recalcuate now button.
* @param object $quizstats the overall quiz statistics.
* @param int $quizid the quiz id.
* @param int $currentgroup the id of the currently selected group, or 0.
* @param array $groupstudents ids of students in the group.
* @param bool $useallattempts whether to use all attempts, instead of just
* first attempts.
* @param object $quizstats the overall quiz statistics.
* @param int $quizid the quiz id.
* @param int $currentgroup the id of the currently selected group, or 0.
* @param array $groupstudents ids of students in the group.
* @param bool $useallattempts whether to use all attempts, instead of just
* first attempts.
* @param moodle_url $reporturl url for this report
* @return string a HTML snipped saying when the stats were last computed,
* or blank if that is not appropriate.
*/
@ -1008,28 +933,13 @@ class quiz_statistics_report extends quiz_default_report {
/**
* Clear the cached data for a particular report configuration. This will
* trigger a re-computation the next time the report is displayed.
* @param int $quizid the quiz id.
* @param int $currentgroup a group id, or 0.
* @param bool $useallattempts whether all attempts, or just first attempts are included.
* @param $qubaids qubaid_condition
*/
protected function clear_cached_data($quizid, $currentgroup, $useallattempts) {
protected function clear_cached_data($qubaids) {
global $DB;
$todelete = $DB->get_records_menu('quiz_statistics', array('quizid' => $quizid,
'groupid' => $currentgroup, 'allattempts' => $useallattempts), '', 'id, 1');
if (!$todelete) {
return;
}
list($todeletesql, $todeleteparams) = $DB->get_in_or_equal(array_keys($todelete));
$DB->delete_records_select('quiz_question_statistics',
'quizstatisticsid ' . $todeletesql, $todeleteparams);
$DB->delete_records_select('quiz_question_response_stats',
'quizstatisticsid ' . $todeletesql, $todeleteparams);
$DB->delete_records_select('quiz_statistics',
'id ' . $todeletesql, $todeleteparams);
$DB->delete_records('quiz_statistics', array('hashcode' => $qubaids->get_hash_code()));
$DB->delete_records('question_statistics', array('hashcode' => $qubaids->get_hash_code()));
$DB->delete_records('question_response_analysis', array('hashcode' => $qubaids->get_hash_code()));
}
/**
@ -1067,42 +977,3 @@ class quiz_statistics_report extends quiz_default_report {
}
}
function quiz_statistics_attempts_sql($quizid, $currentgroup, $groupstudents,
$allattempts = true, $includeungraded = false) {
global $DB;
$fromqa = '{quiz_attempts} quiza ';
$whereqa = 'quiza.quiz = :quizid AND quiza.preview = 0 AND quiza.state = :quizstatefinished';
$qaparams = array('quizid' => $quizid, 'quizstatefinished' => quiz_attempt::FINISHED);
if (!empty($currentgroup) && $groupstudents) {
list($grpsql, $grpparams) = $DB->get_in_or_equal(array_keys($groupstudents),
SQL_PARAMS_NAMED, 'u');
$whereqa .= " AND quiza.userid $grpsql";
$qaparams += $grpparams;
}
if (!$allattempts) {
$whereqa .= ' AND quiza.attempt = 1';
}
if (!$includeungraded) {
$whereqa .= ' AND quiza.sumgrades IS NOT NULL';
}
return array($fromqa, $whereqa, $qaparams);
}
/**
* Return a {@link qubaid_condition} from the values returned by
* {@link quiz_statistics_attempts_sql}
* @param string $fromqa from quiz_statistics_attempts_sql.
* @param string $whereqa from quiz_statistics_attempts_sql.
*/
function quiz_statistics_qubaids_condition($quizid, $currentgroup, $groupstudents,
$allattempts = true, $includeungraded = false) {
list($fromqa, $whereqa, $qaparams) = quiz_statistics_attempts_sql($quizid, $currentgroup,
$groupstudents, $allattempts, $includeungraded);
return new qubaid_join($fromqa, 'quiza.uniqueid', $whereqa, $qaparams);
}

41
mod/quiz/report/statistics/statistics_graph.php
View File

@ -33,30 +33,14 @@ require_once(dirname(__FILE__) . '/../../../../config.php');
require_once($CFG->libdir . '/graphlib.php');
require_once($CFG->dirroot . '/mod/quiz/locallib.php');
require_once($CFG->dirroot . '/mod/quiz/report/reportlib.php');
/**
* This helper function returns a sequence of colours each time it is called.
* Used for chooseing colours for graph data series.
* @return string colour name.
*/
function graph_get_new_colour() {
static $colourindex = -1;
$colours = array('red', 'green', 'yellow', 'orange', 'purple', 'black',
'maroon', 'blue', 'ltgreen', 'navy', 'ltred', 'ltltgreen', 'ltltorange',
'olive', 'gray', 'ltltred', 'ltorange', 'lime', 'ltblue', 'ltltblue');
$colourindex = ($colourindex + 1) % count($colours);
return $colours[$colourindex];
}
require_once($CFG->dirroot . '/mod/quiz/report/statistics/statisticslib.php');
// Get the parameters.
$quizstatisticsid = required_param('id', PARAM_INT);
$quizid = required_param('quizid', PARAM_INT);
$currentgroup = required_param('currentgroup', PARAM_INT);
$useallattempts = required_param('useallattempts', PARAM_INT);
// Load enough data to check permissions.
$quizstatistics = $DB->get_record('quiz_statistics', array('id' => $quizstatisticsid));
$quiz = $DB->get_record('quiz', array('id' => $quizstatistics->quizid), '*', MUST_EXIST);
$quiz = $DB->get_record('quiz', array('id' => $quizid), '*', MUST_EXIST);
$cm = get_coursemodule_from_instance('quiz', $quiz->id);
// Check access.
@ -69,14 +53,21 @@ if (groups_get_activity_groupmode($cm)) {
} else {
$groups = array();
}
if ($quizstatistics->groupid && !in_array($quizstatistics->groupid, array_keys($groups))) {
if ($currentgroup && !in_array($currentgroup, array_keys($groups))) {
print_error('groupnotamember', 'group');
}
$groupstudents = get_users_by_capability($modcontext, array('mod/quiz:reviewmyattempts', 'mod/quiz:attempt'),
'', '', '', '', $currentgroup, '', false);
$qubaids = quiz_statistics_qubaids_condition($quizid, $currentgroup, $groupstudents, $useallattempts);
// Load the rest of the required data.
$questions = quiz_report_get_significant_questions($quiz);
$questionstatistics = $DB->get_records_select('quiz_question_statistics',
'quizstatisticsid = ? AND slot IS NOT NULL', array($quizstatistics->id));
// Load enough data to check permissions.
$quizstatistics = $DB->get_record('quiz_statistics', array('hashcode' => $qubaids->get_hash_code()));
$questionstatistics = $DB->get_records_select('question_statistics', 'hashcode = ? AND slot IS NOT NULL',
array($qubaids->get_hash_code()));
// Create the graph, and set the basic options.
$graph = new graph(800, 600);
@ -108,7 +99,7 @@ $xdata = array();
foreach (array_keys($fieldstoplot) as $fieldtoplot) {
$ydata[$fieldtoplot] = array();
$graph->y_format[$fieldtoplot] = array(
'colour' => graph_get_new_colour(),
'colour' => quiz_statistics_graph_get_new_colour(),
'bar' => 'fill',
'shadow_offset' => 1,
'legend' => $fieldstoplot[$fieldtoplot]

2
mod/quiz/report/statistics/statistics_question_table.php
View File

@ -61,7 +61,7 @@ class quiz_statistics_question_table extends flexible_table {
* @param bool $hassubqs
*/
public function question_setup($reporturl, $questiondata,
quiz_statistics_response_analyser $responesstats) {
question_response_analyser $responesstats) {
$this->questiondata = $questiondata;
$this->define_baseurl($reporturl->out());

84
mod/quiz/report/statistics/statisticslib.php Normal file
View File

@ -0,0 +1,84 @@
<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* Common functions for the quiz statistics report.
*
* @package quiz_statistics
* @copyright 2013 The Open University
* @author James Pratt me@jamiep.org
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
function quiz_statistics_attempts_sql($quizid, $currentgroup, $groupstudents,
$allattempts = true, $includeungraded = false) {
global $DB;
$fromqa = '{quiz_attempts} quiza ';
$whereqa = 'quiza.quiz = :quizid AND quiza.preview = 0 AND quiza.state = :quizstatefinished';
$qaparams = array('quizid' => (int)$quizid, 'quizstatefinished' => quiz_attempt::FINISHED);
if (!empty($currentgroup) && $groupstudents) {
list($grpsql, $grpparams) = $DB->get_in_or_equal(array_keys($groupstudents),
SQL_PARAMS_NAMED, 'u');
$whereqa .= " AND quiza.userid $grpsql";
$qaparams += $grpparams;
}
if (!$allattempts) {
$whereqa .= ' AND quiza.attempt = 1';
}
if (!$includeungraded) {
$whereqa .= ' AND quiza.sumgrades IS NOT NULL';
}
return array($fromqa, $whereqa, $qaparams);
}
/**
* Return a {@link qubaid_condition} from the values returned by {@link quiz_statistics_attempts_sql}.
*
* @param int $quizid
* @param int $currentgroup
* @param array $groupstudents
* @param bool $allattempts
* @param bool $includeungraded
* @return \qubaid_join
*/
function quiz_statistics_qubaids_condition($quizid, $currentgroup, $groupstudents,
$allattempts = true, $includeungraded = false) {
list($fromqa, $whereqa, $qaparams) = quiz_statistics_attempts_sql($quizid, $currentgroup,
$groupstudents, $allattempts, $includeungraded);
return new qubaid_join($fromqa, 'quiza.uniqueid', $whereqa, $qaparams);
}
/**
* This helper function returns a sequence of colours each time it is called.
* Used for choosing colours for graph data series.
* @return string colour name.
*/
function quiz_statistics_graph_get_new_colour() {
static $colourindex = -1;
$colours = array('red', 'green', 'yellow', 'orange', 'purple', 'black',
'maroon', 'blue', 'ltgreen', 'navy', 'ltred', 'ltltgreen', 'ltltorange',
'olive', 'gray', 'ltltred', 'ltorange', 'lime', 'ltblue', 'ltltblue');
$colourindex = ($colourindex + 1) % count($colours);
return $colours[$colourindex];
}

45
mod/quiz/report/statistics/tests/statistics_test.php
View File

@ -15,7 +15,7 @@
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* Unit tests for (some of) mod/quiz/report/statistics/qstats.php.
* Unit tests for (some of) /question/engine/statistics.php
*
* @package quiz_statistics
* @category phpunit
@ -28,18 +28,18 @@ defined('MOODLE_INTERNAL') || die();
global $CFG;
require_once($CFG->libdir . '/questionlib.php');
require_once($CFG->dirroot . '/mod/quiz/report/statistics/qstats.php');
require_once($CFG->dirroot . '/question/engine/statistics.php');
require_once($CFG->dirroot . '/mod/quiz/locallib.php');
require_once($CFG->dirroot . '/mod/quiz/report/reportlib.php');
/**
* Test helper subclass of quiz_statistics_question_stats
* Test helper subclass of question_statistics
*
* @copyright 2010 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class testable_quiz_statistics_question_stats extends quiz_statistics_question_stats {
class testable_question_statistics extends question_statistics {
public function set_step_data($states) {
$this->lateststeps = $states;
}
@ -47,11 +47,38 @@ class testable_quiz_statistics_question_stats extends quiz_statistics_question_s
protected function get_random_guess_score($questiondata) {
return 0;
}
/**
* @param $qubaids qubaid_condition is ignored in this test
* @return array with three items
* - $lateststeps array of latest step data for the question usages
* - $summarks array of total marks for each usage, indexed by usage id
* - $summarksavg the average of the total marks over all the usages */
protected function get_latest_steps($qubaids) {
$summarks = array();
$fakeusageid = 0;
foreach ($this->lateststeps as $step) {
// The same 'sumgrades' field is available in step data for every slot, we will ignore all slots but slot 1.
// The step for slot 1 is always the first one in the csv file for each usage, we will use that to separate steps from
// each usage.
if ($step->slot == 1) {
$fakeusageid++;
$summarks[$fakeusageid] = $step->sumgrades;
}
unset($step->sumgrades);
$step->questionusageid = $fakeusageid;
}
$summarksavg = array_sum($summarks) / count($summarks);
return array($this->lateststeps, $summarks, $summarksavg);
}
protected function cache_stats($qubaids) {
// No caching wanted for tests.
}
}
/**
* Unit tests for (some of) quiz_statistics_question_stats.
* Unit tests for (some of) question_statistics.
*
* @copyright 2008 Jamie Pratt
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
@ -68,9 +95,9 @@ class quiz_statistics_question_stats_testcase extends basic_testcase {
// Data is taken from questions mostly generated by
// contrib/tools/generators/generator.php.
$questions = $this->get_records_from_csv(__DIR__.'/fixtures/mdl_question.csv');
$this->qstats = new testable_quiz_statistics_question_stats($questions, 22, 10045.45455);
$this->qstats = new testable_question_statistics($questions, 22, 10045.45455);
$this->qstats->set_step_data($steps);
$this->qstats->compute_statistics();
$this->qstats->calculate(null);
// Values expected are taken from contrib/tools/quiz_tools/stats.xls.
$facility = array(0, 0, 0, 0, null, null, null, 41.19318182, 81.36363636,

7
mod/quiz/report/statistics/tests/stats_from_steps_walkthrough_test.php
View File

@ -17,7 +17,7 @@
/**
* Quiz attempt walk through using data from csv file.
*
* @package mod_quiz
* @package quiz_statistics
* @category phpunit
* @copyright 2013 The Open University
* @author Jamie Pratt <me@jamiep.org>
@ -42,7 +42,8 @@ class testable_quiz_statistics_report extends quiz_statistics_report {
public function get_stats($quiz, $useallattempts = true,
$currentgroup = 0, $groupstudents = array(), $nostudentsingroup = false) {
$this->clear_cached_data($quiz->id, $currentgroup, $useallattempts);
$qubaids = quiz_statistics_qubaids_condition($quiz->id, $currentgroup, $groupstudents, $useallattempts);
$this->clear_cached_data($qubaids);
$questions = $this->load_and_initialise_questions_for_calculations($quiz);
return $this->get_quiz_and_questions_stats($quiz, $currentgroup, $nostudentsingroup,
$useallattempts, $groupstudents, $questions);
@ -52,7 +53,7 @@ class testable_quiz_statistics_report extends quiz_statistics_report {
/**
* Quiz attempt walk through using data from csv file.
*
* @package mod_quiz
* @package quiz_statistics
* @category phpunit
* @copyright 2013 The Open University
* @author Jamie Pratt <me@jamiep.org>

4
mod/quiz/report/statistics/version.php
View File

@ -24,7 +24,7 @@
defined('MOODLE_INTERNAL') || die();
$plugin->version = 2013050100;
$plugin->requires = 2013050100;
$plugin->version = 2013092000;
$plugin->requires = 2013092000;
$plugin->cron = 18000;
$plugin->component = 'quiz_statistics';

4
question/engine/bank.php
View File

@ -421,6 +421,10 @@ abstract class question_bank {
// Delete any old question preview that got left in the database.
require_once($CFG->dirroot . '/question/previewlib.php');
question_preview_cron();
// Clear older calculated stats from cache.
require_once($CFG->dirroot . '/question/engine/statisticslib.php');
question_usage_statistics_cron();
}
}

28
question/engine/datalib.php
View File

@ -359,16 +359,16 @@ ORDER BY
* Load information about the latest state of each question from the database.
*
* @param qubaid_condition $qubaids used to restrict which usages are included
* in the query. See {@link qubaid_condition}.
* @param array $slots A list of slots for the questions you want to konw about.
* in the query. See {@link qubaid_condition}.
* @param array $slots A list of slots for the questions you want to konw about.
* @param string|null $fields
* @return array of records. See the SQL in this function to see the fields available.
*/
public function load_questions_usages_latest_steps(qubaid_condition $qubaids, $slots) {
public function load_questions_usages_latest_steps(qubaid_condition $qubaids, $slots, $fields = null) {
list($slottest, $params) = $this->db->get_in_or_equal($slots, SQL_PARAMS_NAMED, 'slot');
$records = $this->db->get_records_sql("
SELECT
qas.id,
if ($fields === null) {
$fields = "qas.id,
qa.id AS questionattemptid,
qa.questionusageid,
qa.slot,
@ -387,7 +387,13 @@ SELECT
qas.state,
qas.fraction,
qas.timecreated,
qas.userid
qas.userid";
}
$records = $this->db->get_records_sql("
SELECT
{$fields}
FROM {$qubaids->from_question_attempts('qa')}
JOIN {question_attempt_steps} qas ON
@ -1458,6 +1464,14 @@ abstract class qubaid_condition {
* @return the params needed by a query that uses {@link usage_id_in()}.
*/
public abstract function usage_id_in_params();
/**
* @return string 40-character hash code that uniquely identifies the combination of properties and class name of this qubaid
* condition.
*/
public function get_hash_code() {
return sha1(serialize($this));
}
}

54
mod/quiz/report/statistics/responseanalysis.php → question/engine/responseanalysis.php
View File

@ -18,9 +18,11 @@
* This file contains the code to analyse all the responses to a particular
* question.
*
* @package quiz_statistics
* @copyright 2010 The Open University
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
* @package core
* @subpackage questionbank
* @copyright 2013 Open University
* @author Jamie Pratt <me@jamiep.org>
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
@ -31,13 +33,13 @@ defined('MOODLE_INTERNAL') || die();
* This class can store and compute the analysis of the responses to a particular
* question.
*
* @copyright 2010 The Open University
* @copyright 2013 Open University
* @author Jamie Pratt <me@jamiep.org>
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class quiz_statistics_response_analyser {
class question_response_analyser {
/** @var object the data from the database that defines the question. */
protected $questiondata;
protected $loaded = false;
/**
* @var array This is a multi-dimensional array that stores the results of
@ -119,9 +121,9 @@ class quiz_statistics_response_analyser {
/**
* Analyse all the response data for for all the specified attempts at
* this question.
* @param $qubaids which attempts to consider.
* @param qubaid_condition $qubaids which attempts to consider.
*/
public function analyse($qubaids) {
public function calculate($qubaids) {
// Load data.
$dm = new question_engine_data_mapper();
$questionattempts = $dm->load_attempts_at_question($this->questiondata->id, $qubaids);
@ -130,8 +132,8 @@ class quiz_statistics_response_analyser {
foreach ($questionattempts as $qa) {
$this->add_data_from_one_attempt($qa);
}
$this->store_cached($qubaids);
$this->loaded = true;
}
/**
@ -164,19 +166,16 @@ class quiz_statistics_response_analyser {
}
/**
* Store the computed response analysis in the quiz_question_response_stats
* table.
* @param int $quizstatisticsid the cached quiz statistics to load the
* Store the computed response analysis in the question_response_analysis table.
* @param qubaid_condition $qubaids
* data corresponding to.
* @return bool true if cached data was found in the database and loaded,
* otherwise false, to mean no data was loaded.
* @return bool true if cached data was found in the database and loaded, otherwise false, to mean no data was loaded.
*/
public function load_cached($quizstatisticsid) {
public function load_cached($qubaids) {
global $DB;
$rows = $DB->get_records('quiz_question_response_stats',
array('quizstatisticsid' => $quizstatisticsid,
'questionid' => $this->questiondata->id));
$rows = $DB->get_records('question_response_analysis',
array('hashcode' => $qubaids->get_hash_code(), 'questionid' => $this->questiondata->id));
if (!$rows) {
return false;
}
@ -186,28 +185,22 @@ class quiz_statistics_response_analyser {
$this->responses[$row->subqid][$row->aid][$row->response]->count = $row->rcount;
$this->responses[$row->subqid][$row->aid][$row->response]->fraction = $row->credit;
}
$this->loaded = true;
return true;
}
/**
* Store the computed response analysis in the quiz_question_response_stats
* table.
* @param int $quizstatisticsid the cached quiz statistics this correspons to.
* Store the computed response analysis in the question_response_analysis table.
* @param qubaid_condition $qubaids
*/
public function store_cached($quizstatisticsid) {
public function store_cached($qubaids) {
global $DB;
if (!$this->loaded) {
throw new coding_exception(
'Question responses have not been analyised. Cannot store in the database.');
}
$cachetime = time();
foreach ($this->responses as $subpartid => $partdata) {
foreach ($partdata as $responseclassid => $classdata) {
foreach ($classdata as $response => $data) {
$row = new stdClass();
$row->quizstatisticsid = $quizstatisticsid;
$row->hashcode = $qubaids->get_hash_code();
$row->questionid = $this->questiondata->id;
$row->subqid = $subpartid;
if ($responseclassid === '') {
@ -218,7 +211,8 @@ class quiz_statistics_response_analyser {
$row->response = $response;
$row->rcount = $data->count;
$row->credit = $data->fraction;
$DB->insert_record('quiz_question_response_stats', $row, false);
$row->timemodified = $cachetime;
$DB->insert_record('question_response_analysis', $row, false);
}
}
}

447
question/engine/statistics.php Normal file
View File

@ -0,0 +1,447 @@
<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* Question statistics calculations class. Used in the quiz statistics report but also available for use elsewhere.
*
* @package core
* @subpackage questionbank
* @copyright 2013 Open University
* @author Jamie Pratt <me@jamiep.org>
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
defined('MOODLE_INTERNAL') || die();
/**
* This class has methods to compute the question statistics from the raw data.
*
* @copyright 2013 Open University
* @author Jamie Pratt <me@jamiep.org>
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
class question_statistics {
public $questions;
public $subquestions = array();
protected $summarksavg;
protected $sumofmarkvariance = 0;
protected $randomselectors = array();
/**
* Constructor.
*
* @param $questions array the main questions indexed by slot.
*/
public function __construct($questions) {
foreach ($questions as $slot => $question) {
$question->_stats = $this->make_blank_question_stats();
$question->_stats->questionid = $question->id;
$question->_stats->slot = $slot;
}
$this->questions = $questions;
}
/**
* @return object ready to hold all the question statistics.
*/
protected function make_blank_question_stats() {
$stats = new stdClass();
$stats->slot = null;
$stats->s = 0;
$stats->totalmarks = 0;
$stats->totalothermarks = 0;
$stats->markvariancesum = 0;
$stats->othermarkvariancesum = 0;
$stats->covariancesum = 0;
$stats->covariancemaxsum = 0;
$stats->subquestion = false;
$stats->subquestions = '';
$stats->covariancewithoverallmarksum = 0;
$stats->randomguessscore = null;
$stats->markarray = array();
$stats->othermarksarray = array();
return $stats;
}
/**
* @param $qubaids qubaid_condition
* @return array with three items
* - $lateststeps array of latest step data for the question usages
* - $summarks array of total marks for each usage, indexed by usage id
* - $summarksavg the average of the total marks over all the usages
*/
protected function get_latest_steps($qubaids) {
$dm = new question_engine_data_mapper();
$fields = " qas.id,
qa.questionusageid,
qa.questionid,
qa.slot,
qa.maxmark,
qas.fraction * qa.maxmark as mark";
$lateststeps = $dm->load_questions_usages_latest_steps($qubaids, array_keys($this->questions), $fields);
$summarks = array();
if ($lateststeps) {
foreach ($lateststeps as $step) {
if (!isset($summarks[$step->questionusageid])) {
$summarks[$step->questionusageid] = 0;
}
$summarks[$step->questionusageid] += $step->mark;
}
$summarksavg = array_sum($summarks) / count($summarks);
} else {
$summarksavg = null;
}
return array($lateststeps, $summarks, $summarksavg);
}
/**
* @param $qubaids qubaid_condition
*/
public function calculate($qubaids) {
set_time_limit(0);
list($lateststeps, $summarks, $summarksavg) = $this->get_latest_steps($qubaids);
if ($lateststeps) {
$subquestionstats = array();
// Compute the statistics of position, and for random questions, work
// out which questions appear in which positions.
foreach ($lateststeps as $step) {
$this->initial_steps_walker($step, $this->questions[$step->slot]->_stats, $summarks);
// If this is a random question what is the real item being used?
if ($step->questionid != $this->questions[$step->slot]->id) {
if (!isset($subquestionstats[$step->questionid])) {
$subquestionstats[$step->questionid] = $this->make_blank_question_stats();
$subquestionstats[$step->questionid]->questionid = $step->questionid;
$subquestionstats[$step->questionid]->usedin = array();
$subquestionstats[$step->questionid]->subquestion = true;
$subquestionstats[$step->questionid]->differentweights = false;
$subquestionstats[$step->questionid]->maxmark = $step->maxmark;
} else if ($subquestionstats[$step->questionid]->maxmark != $step->maxmark) {
$subquestionstats[$step->questionid]->differentweights = true;
}
$this->initial_steps_walker($step, $subquestionstats[$step->questionid], $summarks, false);
$number = $this->questions[$step->slot]->number;
$subquestionstats[$step->questionid]->usedin[$number] = $number;
$randomselectorstring = $this->questions[$step->slot]->category .
'/' . $this->questions[$step->slot]->questiontext;
if (!isset($this->randomselectors[$randomselectorstring])) {
$this->randomselectors[$randomselectorstring] = array();
}
$this->randomselectors[$randomselectorstring][$step->questionid] =
$step->questionid;
}
}
foreach ($this->randomselectors as $key => $notused) {
ksort($this->randomselectors[$key]);
}
// Compute the statistics of question id, if we need any.
$this->subquestions = question_load_questions(array_keys($subquestionstats));
foreach ($this->subquestions as $qid => $subquestion) {
$subquestion->_stats = $subquestionstats[$qid];
$subquestion->maxmark = $subquestion->_stats->maxmark;
$subquestion->_stats->randomguessscore = $this->get_random_guess_score($subquestion);
$this->initial_question_walker($subquestion->_stats);
if ($subquestionstats[$qid]->differentweights) {
// TODO output here really sucks, but throwing is too severe.
global $OUTPUT;
echo $OUTPUT->notification(
get_string('erroritemappearsmorethanoncewithdifferentweight',
'quiz_statistics', $this->subquestions[$qid]->name));
}
if ($subquestion->_stats->usedin) {
sort($subquestion->_stats->usedin, SORT_NUMERIC);
$subquestion->_stats->positions = implode(',', $subquestion->_stats->usedin);
} else {
$subquestion->_stats->positions = '';
}
}
// Finish computing the averages, and put the subquestion data into the
// corresponding questions.
// This cannot be a foreach loop because we need to have both
// $question and $nextquestion available, but apart from that it is
// foreach ($this->questions as $qid => $question).
reset($this->questions);
while (list($slot, $question) = each($this->questions)) {
$nextquestion = current($this->questions);
$question->_stats->positions = $question->number;
$question->_stats->maxmark = $question->maxmark;
$question->_stats->randomguessscore = $this->get_random_guess_score($question);
$this->initial_question_walker($question->_stats);
if ($question->qtype == 'random') {
$randomselectorstring = $question->category.'/'.$question->questiontext;
if ($nextquestion && $nextquestion->qtype == 'random') {
$nextrandomselectorstring = $nextquestion->category . '/' .
$nextquestion->questiontext;
if ($randomselectorstring == $nextrandomselectorstring) {
continue; // Next loop iteration.
}
}
if (isset($this->randomselectors[$randomselectorstring])) {
$question->_stats->subquestions = implode(',',
$this->randomselectors[$randomselectorstring]);
}
}
}
// Go through the records one more time.
foreach ($lateststeps as $step) {
$this->secondary_steps_walker($step, $this->questions[$step->slot]->_stats, $summarks, $summarksavg);
if ($this->questions[$step->slot]->qtype == 'random') {
$this->secondary_steps_walker($step, $this->subquestions[$step->questionid]->_stats, $summarks, $summarksavg);
}
}
$sumofcovariancewithoverallmark = 0;
foreach ($this->questions as $slot => $question) {
$this->secondary_question_walker($question->_stats);
$this->sumofmarkvariance += $question->_stats->markvariance;
if ($question->_stats->covariancewithoverallmark >= 0) {
$sumofcovariancewithoverallmark +=
sqrt($question->_stats->covariancewithoverallmark);
$question->_stats->negcovar = 0;
} else {
$question->_stats->negcovar = 1;
}
}
foreach ($this->subquestions as $subquestion) {
$this->secondary_question_walker($subquestion->_stats);
}
foreach ($this->questions as $question) {
if ($sumofcovariancewithoverallmark) {
if ($question->_stats->negcovar) {
$question->_stats->effectiveweight = null;
} else {
$question->_stats->effectiveweight = 100 *
sqrt($question->_stats->covariancewithoverallmark) /
$sumofcovariancewithoverallmark;
}
} else {
$question->_stats->effectiveweight = null;
}
}
$this->cache_stats($qubaids);
}
}
/**
* @param $qubaids qubaid_condition
*/
protected function cache_stats($qubaids) {
global $DB;
$cachetime = time();
foreach ($this->questions as $question) {
$question->_stats->hashcode = $qubaids->get_hash_code();
$question->_stats->timemodified = $cachetime;
$DB->insert_record('question_statistics', $question->_stats, false);
}
foreach ($this->subquestions as $subquestion) {
$subquestion->_stats->hashcode = $qubaids->get_hash_code();
$subquestion->_stats->timemodified = $cachetime;
$DB->insert_record('question_statistics', $subquestion->_stats, false);
}
}
/**
* Update $stats->totalmarks, $stats->markarray, $stats->totalothermarks
* and $stats->othermarksarray to include another state.
*
* @param object $step the state to add to the statistics.
* @param object $stats the question statistics we are accumulating.
* @param array $summarks of the sum of marks for each question usage, indexed by question usage id
* @param bool $positionstat whether this is a statistic of position of question.
*/
protected function initial_steps_walker($step, $stats, $summarks, $positionstat = true) {
$stats->s++;
$stats->totalmarks += $step->mark;
$stats->markarray[] = $step->mark;
if ($positionstat) {
$stats->totalothermarks += $summarks[$step->questionusageid] - $step->mark;
$stats->othermarksarray[] = $summarks[$step->questionusageid] - $step->mark;
} else {
$stats->totalothermarks += $summarks[$step->questionusageid];
$stats->othermarksarray[] = $summarks[$step->questionusageid];
}
}
/**
* Perform some computations on the per-question statistics calculations after
* we have been through all the states.
*
* @param object $stats quetsion stats to update.
*/
protected function initial_question_walker($stats) {
$stats->markaverage = $stats->totalmarks / $stats->s;
if ($stats->maxmark != 0) {
$stats->facility = $stats->markaverage / $stats->maxmark;
} else {
$stats->facility = null;
}
$stats->othermarkaverage = $stats->totalothermarks / $stats->s;
sort($stats->markarray, SORT_NUMERIC);
sort($stats->othermarksarray, SORT_NUMERIC);
}
/**
* Now we know the averages, accumulate the date needed to compute the higher
* moments of the question scores.
*
* @param object $step the state to add to the statistics.
* @param object $stats the question statistics we are accumulating.
* @param array $summarks of the sum of marks for each question usage, indexed by question usage id
* @param float $summarksavg the average sum of marks for all question usages
*/
protected function secondary_steps_walker($step, $stats, $summarks, $summarksavg) {
$markdifference = $step->mark - $stats->markaverage;
if ($stats->subquestion) {
$othermarkdifference = $summarks[$step->questionusageid] - $stats->othermarkaverage;
} else {
$othermarkdifference = $summarks[$step->questionusageid] - $step->mark -
$stats->othermarkaverage;
}
$overallmarkdifference = $summarks[$step->questionusageid] - $summarksavg;
$sortedmarkdifference = array_shift($stats->markarray) - $stats->markaverage;
$sortedothermarkdifference = array_shift($stats->othermarksarray) -
$stats->othermarkaverage;
$stats->markvariancesum += pow($markdifference, 2);
$stats->othermarkvariancesum += pow($othermarkdifference, 2);
$stats->covariancesum += $markdifference * $othermarkdifference;
$stats->covariancemaxsum += $sortedmarkdifference * $sortedothermarkdifference;
$stats->covariancewithoverallmarksum += $markdifference * $overallmarkdifference;
}
/**
* Perform more per-question statistics calculations.
*
* @param object $stats quetsion stats to update.
*/
protected function secondary_question_walker($stats) {
if ($stats->s > 1) {
$stats->markvariance = $stats->markvariancesum / ($stats->s - 1);
$stats->othermarkvariance = $stats->othermarkvariancesum / ($stats->s - 1);
$stats->covariance = $stats->covariancesum / ($stats->s - 1);
$stats->covariancemax = $stats->covariancemaxsum / ($stats->s - 1);
$stats->covariancewithoverallmark = $stats->covariancewithoverallmarksum /
($stats->s - 1);
$stats->sd = sqrt($stats->markvariancesum / ($stats->s - 1));
} else {
$stats->markvariance = null;
$stats->othermarkvariance = null;
$stats->covariance = null;
$stats->covariancemax = null;
$stats->covariancewithoverallmark = null;
$stats->sd = null;
}
if ($stats->markvariance * $stats->othermarkvariance) {
$stats->discriminationindex = 100 * $stats->covariance /
sqrt($stats->markvariance * $stats->othermarkvariance);
} else {
$stats->discriminationindex = null;
}
if ($stats->covariancemax) {
$stats->discriminativeefficiency = 100 * $stats->covariance /
$stats->covariancemax;
} else {
$stats->discriminativeefficiency = null;
}
}
/**
* @param object $questiondata
* @return number the random guess score for this question.
*/
protected function get_random_guess_score($questiondata) {
return question_bank::get_qtype(
$questiondata->qtype, false)->get_random_guess_score($questiondata);
}
/**
* Used when computing CIC.
* @return number
*/
public function get_sum_of_mark_variance() {
return $this->sumofmarkvariance;
}
/**
* @param qubaid_condition $qubaids
*/
public function get_cached($qubaids) {
global $DB;
$questionstats = $DB->get_records('question_statistics',
array('hashcode' => $qubaids->get_hash_code()));
$subquestionstats = array();
foreach ($questionstats as $stat) {
if ($stat->slot) {
$this->questions[$stat->slot]->_stats = $stat;
} else {
$subquestionstats[$stat->questionid] = $stat;
}
}
if (!empty($subquestionstats)) {
$subqstofetch = array_keys($subquestionstats);
$this->subquestions = question_load_questions($subqstofetch);
foreach ($this->subquestions as $subqid => $subq) {
$this->subquestions[$subqid]->_stats = $subquestionstats[$subqid];
$this->subquestions[$subqid]->maxmark = $subq->defaultmark;
}
}
}
}

46
question/engine/statisticslib.php Normal file
View File

@ -0,0 +1,46 @@
<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
/**
* Functions common to the question usage statistics code.
*
* @package moodlecore
* @subpackage questionbank
* @copyright 2013 The Open University
* @author Jamie Pratt <me@jamiep.org>
* @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
*/
defined('MOODLE_INTERNAL') || die();
/**
* Question statistics cron code. Deletes cached stats more than a certain age.
*/
function question_usage_statistics_cron() {
global $DB;
$expiretime = time() - 5*HOURSECS;
mtrace("\n Cleaning up old question statistics cache records...", '');
$DB->delete_records_select('question_statistics', 'timemodified < ?', array($expiretime));
$DB->delete_records_select('question_response_analysis', 'timemodified < ?', array($expiretime));
mtrace('done.');
return true;
}

2
version.php
View File

@ -29,7 +29,7 @@
defined('MOODLE_INTERNAL') || die();
$version = 2013092000.00; // YYYYMMDD = weekly release date of this DEV branch.
$version = 2013092000.01; // YYYYMMDD = weekly release date of this DEV branch.
// RR = release increments - 00 in DEV branches.
// .XX = incremental changes.