Multiple Choice

Reference: (link)

The multiple choice only requires you to modify:

Folder/File Name	Usage
if this is a standalone problem: info.json	The information of the question such as title, topic, tags, and uuid.
if you want have conditional answers: server.py	Set up the condition for answers
question.html	The main body of the question

A pl-multiple-choice element selects one correct answer and zero or more incorrect answers and displays them in a random order as radio buttons.

An example of the question.html

<pl-question-panel>
	<p> 
	This is the problem statement.
	</p>
</pl-question-panel>

<pl-question-panel><hr></pl-question-panel>
<pl-question-panel>
	<p>
	    (a) 1+1=?
	</p>
</pl-question-panel>

<div class="card my-2">
    <div class="card-body">
        <pl-question-panel>
            <p> 
                The answer is:
            </p>
        </pl-question-panel>

        <pl-multiple-choice answers-name="answer_a" weight="2">
        	<pl-answer correct="false"> 1 </pl-answer>
		    	<pl-answer correct="false"> 3 </pl-answer> 
		    	<pl-answer correct="true"> 2 </pl-answer> 
        </pl-multiple-choice>
    </div>
</div>

The problem will be:

When you clicked the correct answer:

Conditional Answers

Assume we want to have conditional answers, for instance, the answers of the multiple choice depend on the previous answer. Here we have an example, the p-value is calculated from previous answer (we omiss how to get p, but use the function sample as an example). Here the p (in Python is p, in R is p_r, use the function ans=list(...) to convert) value could be 0.5 or 0.005. The idea is:

If p<0.01, the correct answer is True (reject), and vice versa.

server.py

Please note the order for the conditional answers, otherwise the commands data['correct_answers'] = ans and data["params"] = ans will overwrite your conditional answers.

import prairielearn as pl
def generate(data):
    values = robjects.r("""
        p_r = sample(c(0.005,0.5),1)
        
        # Export
        list(  
             ans = list(p=round(p_r,digits=3))
       )
    """)

    ans = values[0]
    # Convert from R lists to python dictionaries
    ans = { key : ans.rx2(key)[0] for key in ans.names }
    # Setup output dictionaries
    data['correct_answers'] = ans
    data["params"] = ans
		
    # Here is the start for the conditional answers
    if data['correct_answers']["p"]<0.01:
        # The option "True" in question.html is correct
        data['params']["answer_b_true"] = True
        data['params']["answer_b_false"] = False
    else:
        # The option "True" in question.html is incorrect
        data['params']["answer_b_true"] = False
        data['params']["answer_b_false"] = True

question.html

<pl-question-panel><hr></pl-question-panel>
<pl-question-panel>
    <p>
        (b) If the p-value is ${{params.p}}$, we should reject $H_0$
    </p>
</pl-question-panel>

<div class="card my-2">
    <div class="card-body">
        <pl-question-panel>
            <p> 
                The answer is:
            </p>
        </pl-question-panel>

        <pl-multiple-choice answers-name="answer_b" weight="2">
          <pl-answer correct="{{params.answer_b_true}}"> True </pl-answer>
          <pl-answer correct="{{params.answer_b_false}}"> False </pl-answer> 
        </pl-multiple-choice>
    </div>
</div>

Appearance

• If p-value is 0.005

• If p-value is 0.5

Customizations

Attribute	Type	Default	Description
answers-name	string	—	Variable name to store data in.
weight	integer	1	Weight to use when computing a weighted average score over elements.
inline	boolean	false	List answer choices on a single line instead of as separate paragraphs.
number-answers	integer	special	The total number of answer choices to display. Defaults to displaying one correct answer and all incorrect answers.
fixed-order	boolean	false	Disable the randomization of answer order.

Inside the pl-multiple-choice element, each choice must be specified with a pl-answer that has attributes:

Attribute	Type	Default	Description
correct	boolean	false	Is this a correct answer to the question?