public function display($quiz, $cm, $course) { global $CFG, $DB, $OUTPUT; // Initialise the required data. $this->mode = 'stack'; $this->context = context_module::instance($cm->id); list($currentgroup, $students, $groupstudents, $allowed) = $this->load_relevant_students($cm, $course); $this->qubaids = quiz_statistics_qubaids_condition($quiz->id, $currentgroup, $groupstudents, true); $questionsused = $this->get_stack_questions_used_in_attempt($this->qubaids); $questionid = optional_param('questionid', 0, PARAM_INT); // Display the appropriate page. $this->print_header_and_tabs($cm, $course, $quiz); if (!$questionsused) { $this->display_no_stack_questions(); } else { if (!$questionid) { $this->display_index($questionsused); } else { if (array_key_exists($questionid, $questionsused)) { $this->display_analysis($questionsused[$questionid]); } else { $this->display_unknown_question(); } } } }
public function get_stats($quiz, $whichattempts = QUIZ_GRADEAVERAGE, $groupstudents = array()) { $qubaids = quiz_statistics_qubaids_condition($quiz->id, $groupstudents, $whichattempts); $this->clear_cached_data($qubaids); $questions = $this->load_and_initialise_questions_for_calculations($quiz); return $this->get_quiz_and_questions_stats($quiz, $whichattempts, $groupstudents, $questions); }
/** * Create a quiz add questions to it, walk through quiz attempts and then check results. * * @param PHPUnit_Extensions_Database_DataSet_ITable[] of data read from csv file "questionsXX.csv", * "stepsXX.csv" and "resultsXX.csv". * @dataProvider get_data_for_walkthrough */ public function test_walkthrough_from_csv($quizsettings, $csvdata) { // CSV data files for these tests were generated using : // https://github.com/jamiepratt/moodle-quiz-tools/tree/master/responsegenerator $this->resetAfterTest(true); question_bank::get_qtype('random')->clear_caches_before_testing(); $this->create_quiz($quizsettings, $csvdata['questions']); $attemptids = $this->walkthrough_attempts($csvdata['steps']); $this->check_attempts_results($csvdata['results'], $attemptids); $this->report = new quiz_statistics_report(); $whichattempts = QUIZ_GRADEAVERAGE; $groupstudents = array(); $questions = $this->report->load_and_initialise_questions_for_calculations($this->quiz); list($quizstats, $questionstats, $subquestionstats) = $this->report->get_quiz_and_questions_stats($this->quiz, $whichattempts, $groupstudents, $questions); $qubaids = quiz_statistics_qubaids_condition($this->quiz->id, $groupstudents, $whichattempts); // We will create some quiz and question stat calculator instances and some response analyser instances, just in order // to check the time of the $quizcalc = new quiz_statistics_calculator(); // Should not be a delay of more than one second between the calculation of stats above and here. $this->assertTimeCurrent($quizcalc->get_last_calculated_time($qubaids)); $qcalc = new \core_question\statistics\questions\calculator($questions); $this->assertTimeCurrent($qcalc->get_last_calculated_time($qubaids)); foreach ($questions as $question) { if (!question_bank::get_qtype($question->qtype, false)->can_analyse_responses()) { continue; } $responesstats = new \core_question\statistics\responses\analyser($question); $this->assertTimeCurrent($responesstats->get_last_analysed_time($qubaids)); } // These quiz stats and the question stats found in qstats00.csv were calculated independently in spreadsheet which is // available in open document or excel format here : // https://github.com/jamiepratt/moodle-quiz-tools/tree/master/statsspreadsheet $quizstatsexpected = array('median' => 4.5, 'firstattemptsavg' => 4.617333332, 'allattemptsavg' => 4.617333332, 'firstattemptscount' => 25, 'allattemptscount' => 25, 'standarddeviation' => 0.8117265554, 'skewness' => -0.092502502, 'kurtosis' => -0.7073968557, 'cic' => -87.22309355420001, 'errorratio' => 136.8294900795, 'standarderror' => 1.1106813066); foreach ($quizstatsexpected as $statname => $statvalue) { $this->assertEquals($statvalue, $quizstats->{$statname}, $quizstats->{$statname}, abs($statvalue) * 1.5E-5); } for ($rowno = 0; $rowno < $csvdata['qstats']->getRowCount(); $rowno++) { $slotqstats = $csvdata['qstats']->getRow($rowno); foreach ($slotqstats as $statname => $slotqstat) { if ($statname !== 'slot') { switch ($statname) { case 'covariance': case 'discriminationindex': case 'discriminativeefficiency': case 'effectiveweight': $precision = 1.0E-5; break; default: $precision = 1.0E-6; } $slot = $slotqstats['slot']; $delta = abs($slotqstat) * $precision; $actual = $questionstats[$slot]->{$statname}; $this->assertEquals(floatval($slotqstat), $actual, "{$statname} for slot {$slot}", $delta); } } } }
/** * Compute the quiz statistics. * * @param int $quizid the quiz id. * @param int $whichattempts which attempts to use, represented internally as one of the constants as used in * $quiz->grademethod ie. * QUIZ_GRADEAVERAGE, QUIZ_GRADEHIGHEST, QUIZ_ATTEMPTLAST or QUIZ_ATTEMPTFIRST * we calculate stats based on which attempts would affect the grade for each student. * @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 quiz_statistics_calculated $quizstats The statistics for overall attempt scores. */ public function calculate($quizid, $whichattempts, $groupstudents, $p, $sumofmarkvariance) { $quizstats = new quiz_statistics_calculated($whichattempts); $countsandaverages = $this->attempt_counts_and_averages($quizid, $groupstudents); foreach ($countsandaverages as $propertyname => $value) { $quizstats->{$propertyname} = $value; } $s = $quizstats->s(); if ($s == 0) { return $quizstats; } // Recalculate sql again this time possibly including test for first attempt. list($fromqa, $whereqa, $qaparams) = quiz_statistics_attempts_sql($quizid, $groupstudents, $whichattempts); $quizstats->median = $this->median($s, $fromqa, $whereqa, $qaparams); if ($s > 1) { $powers = $this->sum_of_powers_of_difference_to_mean($quizstats->avg(), $fromqa, $whereqa, $qaparams); $quizstats->standarddeviation = sqrt($powers->power2 / ($s - 1)); // Skewness. if ($s > 2) { // See http://docs.moodle.org/dev/Quiz_item_analysis_calculations_in_practise#Skewness_and_Kurtosis. $m2 = $powers->power2 / $s; $m3 = $powers->power3 / $s; $m4 = $powers->power4 / $s; $k2 = $s * $m2 / ($s - 1); $k3 = $s * $s * $m3 / (($s - 1) * ($s - 2)); if ($k2 != 0) { $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)); $quizstats->kurtosis = $k4 / ($k2 * $k2); } if ($p > 1) { $quizstats->cic = 100 * $p / ($p - 1) * (1 - $sumofmarkvariance / $k2); $quizstats->errorratio = 100 * sqrt(1 - $quizstats->cic / 100); $quizstats->standarderror = $quizstats->errorratio * $quizstats->standarddeviation / 100; } } } } $quizstats->cache(quiz_statistics_qubaids_condition($quizid, $groupstudents, $whichattempts)); return $quizstats; }
protected function analyse_responses($quizstatisticsid, $quizid, $currentgroup, $nostudentsingroup, $useallattempts, $groupstudents, $questions, $subquestions) { $qubaids = quiz_statistics_qubaids_condition( $quizid, $currentgroup, $groupstudents, $useallattempts); $done = array(); foreach ($questions as $question) { if (!question_bank::get_qtype($question->qtype, false)->can_analyse_responses()) { continue; } $done[$question->id] = 1; $responesstats = new quiz_statistics_response_analyser($question); $responesstats->analyse($qubaids); $responesstats->store_cached($quizstatisticsid); } foreach ($subquestions as $question) { if (!question_bank::get_qtype($question->qtype, false)->can_analyse_responses() || isset($done[$question->id])) { continue; } $done[$question->id] = 1; $responesstats = new quiz_statistics_response_analyser($question); $responesstats->analyse($qubaids); $responesstats->store_cached($quizstatisticsid); } }
$modcontext = context_module::instance($cm->id); require_capability('quiz/statistics:view', $modcontext); if (groups_get_activity_groupmode($cm)) { $groups = groups_get_activity_allowed_groups($cm); } else { $groups = array(); } if ($currentgroup && !in_array($currentgroup, array_keys($groups))) { print_error('groupnotamember', 'group'); } if (empty($currentgroup)) { $groupstudents = array(); } else { $groupstudents = get_users_by_capability($modcontext, array('mod/quiz:reviewmyattempts', 'mod/quiz:attempt'), '', '', '', '', $currentgroup, '', false); } $qubaids = quiz_statistics_qubaids_condition($quizid, $groupstudents, $whichattempts); // Load the rest of the required data. $questions = quiz_report_get_significant_questions($quiz); // Only load main question not sub questions. $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); $graph->parameter['title'] = ''; $graph->parameter['y_label_left'] = '%'; $graph->parameter['x_label'] = get_string('position', 'quiz_statistics'); $graph->parameter['y_label_angle'] = 90; $graph->parameter['x_label_angle'] = 0; $graph->parameter['x_axis_angle'] = 60; $graph->parameter['legend'] = 'outside-right'; $graph->parameter['legend_border'] = 'black'; $graph->parameter['legend_offset'] = 4;
/** * Get the quiz and question statistics, either by loading the cached results, * or by recomputing them. * * @param object $quiz the quiz settings. * @param string $whichattempts which attempts to use, represented internally as one of the constants as used in * $quiz->grademethod ie. * QUIZ_GRADEAVERAGE, QUIZ_GRADEHIGHEST, QUIZ_ATTEMPTLAST or QUIZ_ATTEMPTFIRST * we calculate stats based on which attempts would affect the grade for each student. * @param string $whichtries which tries to analyse for response analysis. Will be one of * question_attempt::FIRST_TRY, LAST_TRY or ALL_TRIES. * @param array $groupstudents students in this group. * @param array $questions full question data. * @param \core\progress\base|null $progress * @return array with 2 elements: - $quizstats The statistics for overall attempt scores. * - $questionstats \core_question\statistics\questions\all_calculated_for_qubaid_condition */ public function get_all_stats_and_analysis($quiz, $whichattempts, $whichtries, $groupstudents, $questions, $progress = null) { if ($progress === null) { $progress = new \core\progress\none(); } $qubaids = quiz_statistics_qubaids_condition($quiz->id, $groupstudents, $whichattempts); $qcalc = new \core_question\statistics\questions\calculator($questions, $progress); $quizcalc = new \quiz_statistics\calculator($progress); $progress->start_progress('', 3); if ($quizcalc->get_last_calculated_time($qubaids) === false) { // Recalculate now. $questionstats = $qcalc->calculate($qubaids); $progress->progress(1); $quizstats = $quizcalc->calculate($quiz->id, $whichattempts, $groupstudents, count($questions), $qcalc->get_sum_of_mark_variance()); $progress->progress(2); } else { $quizstats = $quizcalc->get_cached($qubaids); $progress->progress(1); $questionstats = $qcalc->get_cached($qubaids); $progress->progress(2); } if ($quizstats->s()) { $subquestions = $questionstats->get_sub_questions(); $this->analyse_responses_for_all_questions_and_subquestions($questions, $subquestions, $qubaids, $whichtries, $progress); } $progress->progress(3); $progress->end_progress(); return array($quizstats, $questionstats); }
/** * Get the quiz and question statistics, either by loading the cached results, * or by recomputing them. * * @param object $quiz the quiz settings. * @param string $whichattempts which attempts to use, represented internally as one of the constants as used in * $quiz->grademethod ie. * QUIZ_GRADEAVERAGE, QUIZ_GRADEHIGHEST, QUIZ_ATTEMPTLAST or QUIZ_ATTEMPTFIRST * we calculate stats based on which attempts would affect the grade for each student. * @param array $groupstudents students in this group. * @param array $questions full question data. * @return array with 4 elements: * - $quizstats The statistics for overall attempt scores. * - $questionstats array of \core_question\statistics\questions\calculated objects keyed by slot. * - $subquestionstats array of \core_question\statistics\questions\calculated_for_subquestion objects keyed by question id. */ public function get_quiz_and_questions_stats($quiz, $whichattempts, $groupstudents, $questions) { $qubaids = quiz_statistics_qubaids_condition($quiz->id, $groupstudents, $whichattempts); $qcalc = new \core_question\statistics\questions\calculator($questions); $quizcalc = new quiz_statistics_calculator(); if ($quizcalc->get_last_calculated_time($qubaids) === false) { // Recalculate now. list($questionstats, $subquestionstats) = $qcalc->calculate($qubaids); $quizstats = $quizcalc->calculate($quiz->id, $whichattempts, $groupstudents, count($questions), $qcalc->get_sum_of_mark_variance()); if ($quizstats->s()) { $this->analyse_responses_for_all_questions_and_subquestions($qubaids, $questions, $subquestionstats); } } else { $quizstats = $quizcalc->get_cached($qubaids); list($questionstats, $subquestionstats) = $qcalc->get_cached($qubaids); } return array($quizstats, $questionstats, $subquestionstats); }
/** * Check the question stats and the response counts used in the statistics report. If the appropriate files exist in fixtures/. * * @param PHPUnit_Extensions_Database_DataSet_ITable[] $csvdata Data loaded from csv files for this test. * @param string $whichattempts * @param string $whichtries * @param \core\dml\sql_join $groupstudentsjoins * @return array with contents 0 => $questions, 1 => $quizstats, 2=> $questionstats, 3=> $qubaids Might be needed for further * testing. */ protected function check_stats_calculations_and_response_analysis($csvdata, $whichattempts, $whichtries, \core\dml\sql_join $groupstudentsjoins) { $this->report = new quiz_statistics_report(); $questions = $this->report->load_and_initialise_questions_for_calculations($this->quiz); list($quizstats, $questionstats) = $this->report->get_all_stats_and_analysis($this->quiz, $whichattempts, $whichtries, $groupstudentsjoins, $questions); $qubaids = quiz_statistics_qubaids_condition($this->quiz->id, $groupstudentsjoins, $whichattempts); // We will create some quiz and question stat calculator instances and some response analyser instances, just in order // to check the last analysed time then returned. $quizcalc = new \quiz_statistics\calculator(); // Should not be a delay of more than one second between the calculation of stats above and here. $this->assertTimeCurrent($quizcalc->get_last_calculated_time($qubaids)); $qcalc = new \core_question\statistics\questions\calculator($questions); $this->assertTimeCurrent($qcalc->get_last_calculated_time($qubaids)); if (isset($csvdata['responsecounts'])) { $this->check_response_counts($csvdata['responsecounts'], $qubaids, $questions, $whichtries); } if (isset($csvdata['qstats'])) { $this->check_question_stats($csvdata['qstats'], $questionstats); return array($questions, $quizstats, $questionstats, $qubaids); } return array($questions, $quizstats, $questionstats, $qubaids); }