MultipleChoiceProblems

Multiple Choice Problems: PG Code Snippet

This code snippet shows the essential PG code to include a multiple-choice question in a problem.

For an example of a multiple choice problem in which the choices are graphs, see Example 1 of GraphsInTables

Note that in this example we use old-style multiple choice answer objects. The new-style MathObjects have a multiple choice object as well, but its behavior is sufficiently different than that suggested here that is not documented here.

PG problem file Explanation
```DOCUMENT();

"PGstandard.pl",
"PGchoicemacros.pl",
);

TEXT(beginproblem());
```

Initialization: Include `PGchoicemacros.pl` in the list of loaded macro files.

```\$mc = new_multiple_choice();
\$mc->qa(
"blue"
);
\$mc->extra(
"red",
"green",
);
\$mc->makeLast("none of the above");
```

Setup: Create a new multiple choice object with `new_multiple_choice`, and then store the question and correct answer with the `qa` method. Other answers are specified as a list of arguments to the `extra` method. To force an answer (either a new extra answer, or the correct answer) to appear last in the list of options, use the `makeLast` method. All other answers will be scrambled when the multiple choice problem is shown to students.

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: In the text section we print the question and answers.

```install_problem_grader(~~&std_problem_grader);

ENDDOCUMENT();
```

Answer Evaluation: Use the standard problem grader to give credit only if all answers are correct, and do not give feedback on partial correct answers. Otherwise, students can use the feedback or the partial credit received to guess and check if their answers are correct. We grade the problem with `radio_cmp`.