Difference between revisions of "MultipleSelectProblems"

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<h2>Multiple Select Problems (or Checkbox Multiple Choice or Select All That Apply): PG Code Snippet</h2>
+
<h2>Multiple Select Problems (or Checkbox Multiple Choice or Select All That Apply)</h2>
   
 
<p style="background-color:#eeeeee;border:black solid 1px;padding:3px;">
 
<p style="background-color:#eeeeee;border:black solid 1px;padding:3px;">
<em>This code snippet shows the essential PG code to include multiple select question (or checkbox multiple choice or select all that apply) in a problem. A multiple choice question has only one correct answer, whereas a checkbox multiple choice question may require several items to be selected at the same time to be correct. Note that these are <b>insertions</b>, not a complete PG file. This code will have to be incorporated into the problem file on which you are working.</em>
+
<em>This code snippet shows the essential PG code to include multiple select question (or checkbox multiple choice or select all that apply) in a problem. A multiple choice question has only one correct answer, whereas a checkbox multiple choice question may require several items to be selected at the same time to be correct. </em>
 
</p>
 
</p>
   
 
<p>
 
<p>
Note that in this example we use old-style checkbox multiple choice answer objects. The new-style MathObjects do not yet have a checkbox multiple choice answer object yet.
+
Note that in this example we use old-style checkbox multiple choice answer objects. The new-style MathObjects do not yet have a checkbox multiple choice answer object.
 
</p>
 
</p>
   
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<pre>
 
<pre>
 
DOCUMENT();
 
DOCUMENT();
  +
 
loadMacros(
 
loadMacros(
"PG.pl",
+
"PGstandard.pl",
"PGbasicmacros.pl",
 
 
"PGchoicemacros.pl",
 
"PGchoicemacros.pl",
"PGanswermacros.pl"
 
  +
"PGcourse.pl",
 
);
 
);
# Do not show which answers are incorrect.
 
  +
$showPartialCorrectAnswers = 0;
 
  +
TEXT(beginproblem());
 
</pre>
 
</pre>
 
</td>
 
</td>
 
<td style="background-color:#ccffcc;padding:7px;">
 
<td style="background-color:#ccffcc;padding:7px;">
 
<p>
 
<p>
In the initialization section of the file we need to include <code>PGchoicemacros.pl</code> and <code>PGanswermacros.pl</code> in our list of loaded macro files. We should also set <code>$showPartialCorrectAnswers = 0;</code> to hide the correct answers from students until they have answered everything correctly.
 
  +
<b>Initialization:</b> We must load <code>PGchoicemacros.pl</code> and <code>PGanswermacros.pl</code>.
 
</p>
 
</p>
 
</td>
 
</td>
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<td style="background-color:#ffffdd;border:black 1px dashed;">
 
<td style="background-color:#ffffdd;border:black 1px dashed;">
 
<pre>
 
<pre>
# Make a new checkbox multiple choice
 
  +
$mc = new_checkbox_multiple_choice();
$cmc = new_checkbox_multiple_choice();
 
  +
$mc -> qa (
# $cmc now "contains" the checkbox multiple choice object.
 
  +
"Select all expressions that are equivalent to
 
  +
\( e^{x^2 + 1/x} \). There may be more than
# Insert a question and matching answers in the q/a list
 
  +
one correct answer.",
$cmc -> qa (
 
  +
"\( e^{x^2} e^{1/x} \)$BR",
"Please select all vectors that are named.", # question
 
  +
"\( e^{x^2} e^{x^{-1}} \)$BR",
"\(\vec{a} = \langle 1, 1, 1 \rangle \)", # a correct answer
 
  +
"\( e^{ (x^3+1) / x } \)$BR",
"\(\vec{n} = \langle 1, -1, 0 \rangle \)", # another correct answer
 
"\(\vec{z} = \langle 0, 0, 0 \rangle \)", # Use " ... " to enter a string
 
# "None of the above",
 
 
);
 
);
# If the only correct answer is "None of the above",
 
  +
$mc -> extra(
# uncomment the "None of the above" string above and
 
  +
"\( \displaystyle \frac{ e^{x^2} }{ e^x } \)$BR",
# remove all other correct answers from the list
 
  +
"\( e^{x^2} + e^{1/x} \)$BR",
 
 
# Insert some incorrect answers
 
$cmc -> extra(
 
"\(\langle -2, 2, 2 \rangle\)",
 
"\(\langle \pi, 4, -1 \rangle\)",
 
 
);
 
);
 
  +
$mc -> makeLast("None of the above");
$cmc->makeLast("None of the above");
 
 
# Note that unlike match lists and select lists, you cannot call qa() again
 
 
</pre>
 
</pre>
 
</td>
 
</td>
 
<td style="background-color:#ffffcc;padding:7px;">
 
<td style="background-color:#ffffcc;padding:7px;">
 
<p>
 
<p>
In the problem set-up, we create a new checkbox multiple choice object with <code>new_checkbox_multiple_choice</code>, and then store the question and correct answer with the <code>qa</code> method. Other answers are specified as a list of arguments to the <code>extra</code> method. To force an answer (either a new extra answer, or the correct answer) to appear last in the list of options, use the <code>makeLast</code> method. All other answers will be scrambled when the multiple choice problem is shown to students.
 
  +
<b>Setup:</b>
  +
Create a new checkbox multiple choice object named <code>$mc</code> with <code>$mc->new_checkbox_multiple_choice();</code>.
  +
</p>
  +
<p>
  +
Use the question and answer method <code>qa( )</code> to store the question string and correct answer strings in <code>$mc</code>. For example, <code>$mc->qa("question","correct answer 1","correct answer 2");</code>. Note that unlike match lists and select lists, you cannot call the <code>qa( )</code> method again. If you include math symbols you should switch to LaTeX mode
  +
<code CLASS="tex2math_ignore">\( \)</code>, and use <code>\displaystyle</code> with extra spacing <code>$BR</code> after each entry, if necessary. For example, <code CLASS="tex2math_ignore">$mc->qa("question", "\( x^2 \) $BR", "\( \displaystyle \frac{x^2}{4-x} \) $BR" );</code>
  +
</p>
  +
<p>
  +
Incorrect answers are specified as a list of string arguments to the <code>extra( )</code> method.
  +
</p>
  +
<p>
  +
The arguments of the <code>makeLast( )</code> method will appear at the end of the list and will not be shuffled, unlike the arguments of <code>extra( )</code>, which are shuffled. The arguments to <code>makeLast( )</code> can either be a new extra answers or only the correct answer. For example, if the only correct answer is "None of the above", use
  +
<pre>
  +
$mc->qa("question","None of the above");
  +
$mc->extra("very wrong","distractor","red herring");
  +
$mc->makeLast("None of the above");
  +
</pre>
  +
</p>
  +
<p>
  +
To make answers appear in a certain order (e.g., Yes followed by No and Maybe), use <code>$mc->qa("question","Yes"); $mc->makeLast("Yes","No","Maybe");</code> and do not use <code>extra( )</code> at all. In this case, to randomize the question and answer, where the answer to question 1 is Yes and the answer to question 2 is No, use
  +
<pre>
  +
@quest = ("question 1","question 2");
  +
@ans = ("Yes","No");
  +
$pick = random(0,1,1);
  +
$mc->new_checkbox_multiple_choice();
  +
$mc->qa($quest[$pick],$ans[$pick]);
  +
$mc->makeLast("Yes","No","Maybe");
  +
</pre>
 
</p>
 
</p>
 
</td>
 
</td>
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<td style="background-color:#ffdddd;border:black 1px dashed;">
 
<td style="background-color:#ffdddd;border:black 1px dashed;">
 
<pre>
 
<pre>
TEXT(beginproblem());
 
 
# Print the text using $cmc->print_q() for the questions and
 
# $cmc->print_a() to print the answers.
 
 
BEGIN_TEXT
 
BEGIN_TEXT
   
This is a place to insert additional text if you wish.
 
  +
\{ $mc -> print_q() \}
$PAR
 
  +
$BR
\{ $cmc -> print_q() \}
+
\{ $mc -> print_a() \}
$PAR
+
\{ $cmc -> print_a() \}
 
 
END_TEXT
 
END_TEXT
 
</pre>
 
</pre>
 
<td style="background-color:#ffcccc;padding:7px;">
 
<td style="background-color:#ffcccc;padding:7px;">
 
<p>
 
<p>
In the text section we print the question and answers.
 
  +
<b>Main Text:</b> Print the question and answers. Print the question text using <code>$mc->print_q()</code> and
  +
the list of all answers using <code>$mc->print_a()</code>.
 
</p>
 
</p>
 
</td>
 
</td>
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<td style="background-color:#eeddff;border:black 1px dashed;">
 
<td style="background-color:#eeddff;border:black 1px dashed;">
 
<pre>
 
<pre>
# Enter the correct answers to be checked against the answers to the students.
 
  +
install_problem_grader(~~&std_problem_grader);
ANS(checkbox_cmp($cmc->correct_ans));
 
  +
  +
$showPartialCorrectAnswers = 0;
  +
  +
ANS( checkbox_cmp( $mc->correct_ans() ) );
   
 
ENDDOCUMENT();
 
ENDDOCUMENT();
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<td style="background-color:#eeccff;padding:7px;">
 
<td style="background-color:#eeccff;padding:7px;">
 
<p>
 
<p>
And we grade the problem with <code>checkbox_cmp</code>.
 
  +
<b>Answer Evaluation:</b> We use the standard problem grader, an all-or-nothing grader that gives no partial credit, and set <code>$showPartialCorrectAnswers = 0;</code> to withhold credit and hide the correct answers until the student answers everything correctly. Otherwise, the student can use a guess-and-check method to find the correct answers by the partial credit and feedback received. Use the <code>checkbox_cmp</code> answer checker.
 
</p>
 
</p>
  +
<p>See
  +
[https://webwork.maa.org/moodle/mod/forum/discuss.php?d=4999 the linked forum discussion thread] for a technique to give partial credit on such questions.</p>
 
</td>
 
</td>
 
</tr>
 
</tr>

Revision as of 04:53, 17 January 2021

Multiple Select Problems (or Checkbox Multiple Choice or Select All That Apply)

This code snippet shows the essential PG code to include multiple select question (or checkbox multiple choice or select all that apply) in a problem. A multiple choice question has only one correct answer, whereas a checkbox multiple choice question may require several items to be selected at the same time to be correct.

Note that in this example we use old-style checkbox multiple choice answer objects. The new-style MathObjects do not yet have a checkbox multiple choice answer object.

Problem Techniques Index

PG problem file Explanation
DOCUMENT();  

loadMacros(
"PGstandard.pl",
"PGchoicemacros.pl",
"PGcourse.pl",
);

TEXT(beginproblem());

Initialization: We must load PGchoicemacros.pl and PGanswermacros.pl.

$mc = new_checkbox_multiple_choice();
$mc -> qa (
"Select all expressions that are equivalent to  
\( e^{x^2 + 1/x} \).  There may be more than
one correct answer.", 
"\( e^{x^2} e^{1/x} \)$BR",
"\( e^{x^2} e^{x^{-1}} \)$BR",                
"\( e^{ (x^3+1) / x } \)$BR",
);
$mc -> extra(
"\( \displaystyle \frac{ e^{x^2} }{ e^x } \)$BR",
"\( e^{x^2} + e^{1/x} \)$BR",
);
$mc -> makeLast("None of the above");

Setup: Create a new checkbox multiple choice object named $mc with $mc->new_checkbox_multiple_choice();.

Use the question and answer method qa( ) to store the question string and correct answer strings in $mc. For example, $mc->qa("question","correct answer 1","correct answer 2");. Note that unlike match lists and select lists, you cannot call the qa( ) method again. If you include math symbols you should switch to LaTeX mode \( \), and use \displaystyle with extra spacing $BR after each entry, if necessary. For example, $mc->qa("question", "\( x^2 \) $BR", "\( \displaystyle \frac{x^2}{4-x} \) $BR" );

Incorrect answers are specified as a list of string arguments to the extra( ) method.

The arguments of the makeLast( ) method will appear at the end of the list and will not be shuffled, unlike the arguments of extra( ), which are shuffled. The arguments to makeLast( ) can either be a new extra answers or only the correct answer. For example, if the only correct answer is "None of the above", use

$mc->qa("question","None of the above");
$mc->extra("very wrong","distractor","red herring");
$mc->makeLast("None of the above");

To make answers appear in a certain order (e.g., Yes followed by No and Maybe), use $mc->qa("question","Yes"); $mc->makeLast("Yes","No","Maybe"); and do not use extra( ) at all. In this case, to randomize the question and answer, where the answer to question 1 is Yes and the answer to question 2 is No, use

@quest = ("question 1","question 2"); 
@ans = ("Yes","No"); 
$pick = random(0,1,1);
$mc->new_checkbox_multiple_choice();
$mc->qa($quest[$pick],$ans[$pick]);
$mc->makeLast("Yes","No","Maybe");

BEGIN_TEXT

\{ $mc -> print_q() \}
$BR
\{ $mc -> print_a() \}

END_TEXT

Main Text: Print the question and answers. Print the question text using $mc->print_q() and the list of all answers using $mc->print_a().

install_problem_grader(~~&std_problem_grader);

$showPartialCorrectAnswers = 0;

ANS( checkbox_cmp( $mc->correct_ans() ) );

ENDDOCUMENT();

Answer Evaluation: We use the standard problem grader, an all-or-nothing grader that gives no partial credit, and set $showPartialCorrectAnswers = 0; to withhold credit and hide the correct answers until the student answers everything correctly. Otherwise, the student can use a guess-and-check method to find the correct answers by the partial credit and feedback received. Use the checkbox_cmp answer checker.

See the linked forum discussion thread for a technique to give partial credit on such questions.

Problem Techniques Index