weekly release 3.10.4+
[moodle.git] / question / behaviour / interactivecountback / behaviour.php
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d1b7e03d 1<?php
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2// This file is part of Moodle - http://moodle.org/
3//
4// Moodle is free software: you can redistribute it and/or modify
5// it under the terms of the GNU General Public License as published by
6// the Free Software Foundation, either version 3 of the License, or
7// (at your option) any later version.
8//
9// Moodle is distributed in the hope that it will be useful,
10// but WITHOUT ANY WARRANTY; without even the implied warranty of
11// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12// GNU General Public License for more details.
13//
14// You should have received a copy of the GNU General Public License
15// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
16
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17/**
18 * Question behaviour that is like the interactive behaviour, but where the
19 * student is credited for parts of the question they got right on earlier tries.
20 *
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21 * @package qbehaviour
22 * @subpackage interactivecountback
23 * @copyright 2009 The Open University
24 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
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25 */
26
27
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28defined('MOODLE_INTERNAL') || die();
29
1fcf0ca8 30require_once(__DIR__ . '/../interactive/behaviour.php');
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017bc1d9 32
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33/**
34 * Question behaviour for interactive mode with count-back scoring.
35 *
36 * As an example, suppose we have a matching question with 4 parts, and 3 tries
37 * (penalty 1/3), and the question is worth 12 marks (so, 3 marks for each part).
38 * Suppose also that:
39 * - on the first try, the student gets the first two parts right, and the
40 * other two wrong.
41 * - on the second try, they are sure they got the first part right, so keep
42 * their answer the same, but they change their answer to the second part.
43 * They also get the answer to the thrid part right on this try, but still
44 * get the 4th part wrong.
45 * - On the final try, they get the first 3 parts right, but the 4th part still
46 * wrong.
47 * We want to grade them as follows.
48 * - For the first part, they were right first time, and did not change their
49 * answer, so we credit that part as right first time: 3/3
50 * - For the second part, although they were right first time, they then changed
51 * their mind, an only finally got it right on the third try, so 1/3.
52 * - For the third part, they got it right on the second try, and then did not
53 * change their answer, so 2/3.
54 * - For the last part, they were wrong at the last try, so 0/3.
55 * So, total mark is 6/12. (Really, a fraction of 0.5.)
56 *
9bec0e7e 57 * Of course, the details of the grading are actually up to the particular
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58 * question type. The point is that the final grade can take into account all
59 * of the tries the student made.
60 *
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61 * @copyright 2009 The Open University
62 * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
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63 */
64class qbehaviour_interactivecountback extends qbehaviour_interactive {
d1b7e03d 65
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66 public function is_compatible_question(question_definition $question) {
67 return $question instanceof question_automatically_gradable_with_countback;
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68 }
69
70 protected function adjust_fraction($fraction, question_attempt_pending_step $pendingstep) {
71 $totaltries = $this->qa->get_step(0)->get_behaviour_var('_triesleft');
72
73 $responses = array();
74 $lastsave = array();
75 foreach ($this->qa->get_step_iterator() as $step) {
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76 if ($step->has_behaviour_var('submit') &&
77 $step->get_state() != question_state::$invalid) {
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78 $responses[] = $step->get_qt_data();
79 $lastsave = array();
80 } else {
81 $lastsave = $step->get_qt_data();
82 }
83 }
84 $lastresponse = $pendingstep->get_qt_data();
85 if (!empty($lastresponse)) {
86 $responses[] = $lastresponse;
87 } else if (!empty($lastsave)) {
88 $responses[] = $lastsave;
89 }
90
91 return $this->question->compute_final_grade($responses, $totaltries);
92 }
93}