Quiz Item Analysis of Multianswers Question Types
This page described a code proposal to access the embedded questions data in multianswers questiion types so that they can be displayed in the Item analysis report. See http://moodle.org/mod/forum/discuss.php?d=86598#387154
The code is experimental and need more testing and is not optimized.
All question types to be analyzed contain at least one embedded question
If we set this as a general framework, the code will be valid for all question types.
We need a question type function to retrieve the embedded questions
There is actually no question type function to know the number the embedded questions in a question. The default function number_of_embedded_questions() returns 1;
This is not the same as actual_number_of_questions().
We need a convention of how to store the responses from the different embedded questions
The same convention should be used in the $session states and in the get_responses function. The actual responses convention used an array to contains the different answers and put in [''] element the actual response. an example for a numerical question with the tolerance limit
stdClass Object ( [id] => 2312 [responses] => Array ( [6837] => stdClass Object ( [answer] => 1822 (1817..1827) [credit] => 1 ) ) )
In a multianswers qtype the different answers responses are stored in an array as.
stdClass Object ( [id] => 2815 [responses] => Array ( [1] => stdClass Object ( [id] => 2816 [responses] => Array ( [7300] => stdClass Object ( [answer] => Wrong answer [credit] => 0 ) [7302] => stdClass Object ( [answer] => Correct answer [credit] => 1 ) [7305] => stdClass Object ( [answer] => Answer that gives half the credit [credit] => 0.5 ) ) ) [2] => stdClass Object ( [id] => 2817 [responses] => Array ( [7303] => stdClass Object ( [answer] => Wrong answer [credit] => 0 ) [7304] => stdClass Object ( [answer] => Correct answer [credit] => 1 ) ) ) [3] => stdClass Object ( [id] => 2818 [responses] => Array ( [7307] => stdClass Object ( [answer] => 65 (64.9..65.1) [credit] => 1 ) ) ) ) )
So the one question question types responses is tranformed in a similar structure.
The upper example becomes
stdClass Object ( [id] => 2312 [responses] => Array ( [0] => stdClass Object ( [id] => 2312 [responses] => Array ( [6837] => stdClass Object ( [answer] => 1822 (1817..1827) [credit] => 1 ) ) ) ) )
The new array elements the defined the responses of the embedded questions and are put in the questions array as subquestions
foreach ($q->responses as $subquestion => $qresponses ){ foreach ($qresponses->responses as $answer => $r) { $r->count = 0; $questions[$qid]['subquestion'][$subquestion]['responses'][$answer] = $r->answer; $questions[$qid]['subquestion'][$subquestion]['rcounts'][$answer] = 0; $questions[$qid]['subquestion'][$subquestion]['credits'][$answer] = $r->credit; $statsrow[$qid]['subquestion'][$subquestion] = 0; }
For a 1 embedded question question type there is just one subquestion with a $subquestion value of 0.
Check response of each subquestion instead of each question
foreach ($responses as $subquestion => $resp ){ if ($resp) { if ($key = array_search($resp, $questions[$qid]['subquestion'][$subquestion]['responses'])) { $questions[$qid]['subquestion'][$subquestion]['rcounts'][$key]++; } else { $test = new stdClass; $test->responses = $QTYPES[$quizquestions[$i]->qtype]->get_correct_responses($quizquestions[$i], $states[$i]); $test->resp = $resp ; $test->keyresp = $subquestion ; $test->question_qid = &$questions[$qid] ; if ($key = $QTYPES[$quizquestions[$i]->qtype]->check_response($quizquestions[$i], $states[$i], $test))
The check_response of a multianswer question type will use the $subquestion to check the $test->resp agains the correct $states response as the $subquestion values where obtained from the multianswer question. The only requirement is that the multianswer use the same convention in get_all_responses that it uses to create the $states data. For one embeded question types the $subquestion ( 0) is ignored as there is no array in the $states data. The result is stored using the same subquestion convention
{ $questions[$qid]['subquestion'][$subquestion]['rcounts'][$key]++; } else { $questions[$qid]['subquestion'][$subquestion]['responses'][] = $resp; $questions[$qid]['subquestion'][$subquestion]['rcounts'][] = 1; $questions[$qid]['subquestion'][$subquestion]['credits'][] = 0; } } } }
The multianswer should divide the question text in each embedded questions
We need a new questiontype function that will format the question text and return it in an array of the emmbedded questions text ordered as the responses. The default for 1 embedded question is an unique array element.
$qtext1 = $QTYPES[$question->qtype]->print_question_formulation($question, $format_options, $quiz->course) ;
that is used as
$qtext = $qquestion = $qname."\n".$qtext1[0]."\n";
for the first line of a question display. A typical output for a multianswers
Array ( [0] => This question consists of some text with an answer embedded right here [1] => .Then you will have to deal with this short answer [2] => and finally we have a floating point number age )
The table is built also on the subquestion structure
foreach ($q['subquestion']as $key => $qr ){ foreach ($qr['responses'] as $aid=>$resp){ $response = new stdClass; if ($qr['credits'][$aid] <= 0) { $qclass = 'uncorrect'; } elseif ($qr['credits'][$aid] == 1) { $qclass = 'correct'; } else { $qclass = 'partialcorrect'; } $response->credit = '('.format_float($qr['credits'][$aid],2).') '; $response->text = ''.format_text($resp, FORMAT_MOODLE, $format_options, $quiz->course).' '; $count = $qr['rcounts'][$aid].'/'.$q['count']; $response->rcount = $count; $response->rpercent = '('.format_float($qr['rcounts'][$aid]/$q['count']*100,0).'%)'; $responses[$subindex][] = $response; } $subindex++; } $facility = format_float($q['facility']*100,0)."%"; $qsd = format_float($q['qsd'],3); $di = format_float($q['disc_index'],2); $dc = format_float($q['disc_coeff'],2); $response = array_shift($responses[0]); $table->add_data(array($qnumber."\n
".$qicon."\n ".$qreview, $qquestion, $response->text, $response->credit, $response->rcount, $response->rpercent, $facility, $qsd, $di, $dc)); foreach($responses[0] as $response) { $table->add_data(array(, , $response->text, $response->credit, $response->rcount, $response->rpercent, , , , )); } if($subindex >1) { for($i = 1 ; $i < $subindex ; $i++){ $response = array_shift($responses[$i]); $table->add_data(array(, $qtext1[$i], $response->text, $response->credit, $response->rcount, $response->rpercent, , , , )); foreach($responses[$i] as $response) { $table->add_data(array(, , $response->text, $response->credit, $response->rcount, $response->rpercent, , , , )); } } } }