How to start with checkdown

George Moroz



Get the stable version from CRAN:


… or get the development version from GitHub:


1. Demo

The main goal of this package to create checking fields and boxes in rmarkdown or quarto. It can be used in class when teacher share materials and tasks (as an .html page or an .html slides), so student can solve some problems and check their work. It is really important since some students are too shy to ask a question, so you can create tasks that will check on the fly the understanding of the class material and give some hints to those students that get stuck. In contrast to the learnr package the checkdown package works serverlessly without shiny and could be stored as a simple .html page (e. g. on Github Pages). In contrast to the exams output the checkdown package creates interactive auto-grading tasks. The interactive version of the exams output is bind to Blackboard Learn, that is really nice, but looks like an overkill for the simple task that checkdown solves.

Load the library:


1.1 Ask question with the check_question() function

Imagine that we want to create a checkbox with the answer 4. All you need is to create a following chunk in your rmarkdown document:

check_question(answer = 4)

It is possible to change wrong and right answer’s messages using wrong and right arguments of the check_question() function. Let’s create some more questions.

Solve 3+3:

check_question(answer = 6, right = "correct", wrong = "not correct")

Type la-la:

check_question(answer = "la-la")

It is possible to use placeholder argument in order to show what kind of answer you expect:

check_question(answer = "la-la", placeholder = "ta-ta-ta")

Number of answers is not limited:

check_question(answer = 1:5)

It is also possible to create a list of answers for students to choose:

check_question("banana", options = c("apple", "banana", "bread"), type = "select")
check_question("banana", options = c("apple", "banana", "bread"), type = "radio")

check_question(c("banana", "apple"), options = c("apple", "banana", "bread"), type = "checkbox")

If the list of possible answers is small, it is possible to align them in one line using alignment argument:

check_question("banana", options = c("apple", "banana", "bread"), type = "radio", alignment = "horizontal")

You can shuffle answers using the random_answer_order argument:

check_question("banana", options = c("apple", "banana", "bread"), type = "radio", random_answer_order = TRUE)

If you don’t want to give the possibility of automatically check your question, just put NULL in the answer argument:

check_question(NULL, options = c("apple", "banana", "bread"), type = "radio")

There is also an experimental type of question in_order, wheere students need to drag and drop words in the correct order:

check_question(answer = c("What", "do", "you", "think?"), type = "in_order")
you What do think?

In this type you need to provide correct order to the answer argument and options will be shuffled automatically.

In case answers are long, it is possible to use vertical alignment:

check_question(c("heat the water", 
                 "place a tea bag into the cup",
                 "pour the hot water over the tea bag",
                 "steep the tea bag into cup",
                 "remove the tea bag"), 
               type = "in_order", alignment = "vertical")
remove the tea bag
pour the hot water over the tea bag
steep the tea bag into cup
place a tea bag into the cup
heat the water

You can put the question itself within the check_question() function using the title argument.

check_question(answer = 42, title = "Put a number from 1 to 100")
Put a number from 1 to 100

It is possible to put some markdown markup whithin the title argument. Since this argument wraps the form contents with tags, you can redefine it appearance with CSS.

There is an additional function insert_score() that make it possible to add a counter of the correct answers on the page (thanks to Julieblas for an idea). It make sense to use this function inline like here:

Results: 0 out of 13

The previous line was generated with the following code:

#### Results: `r insert_score()` out of 13

This function can be located anywhere on your page (before the questions, after the questions, even in the middle), however right now it doesn’t work, if there are multiple instances of this function call per page.

1.2 Give some hints with the check_hint() function

Sometimes you know in advance what kind of mistakes will your students do. Some students are shy and don’t like asking questions, so hints could partially solve this problem. Again all you need is to create a following chunk with the chunck atribute results='asis' in your rmarkdown document:

check_hint("You can use the rmarkdown package")
Click here to see/close the hint

Of course it is possible to change the message of the part that should be clicked, just use the hint_title argument:

check_hint("You can use the rmarkdown package inside checkdown",
           hint_title = "🔎 CLICK HERE")

By default you need to click on the hint in order to make it appear, but this behaviour can be changed with the type argument:

check_hint("You can use the rmarkdown package inside checkdown",
           hint_title = "🔎 Put mouse over here",
           type = "onmouseover")
🔎 Put mouse over here
check_hint("You can use the rmarkdown package inside checkdown",
           hint_title = "🔎 Double click here",
           type = "ondblclick")
🔎 Double click here

It is possible to use Markdown inside messages:

check_hint("- You can use `markdown` **inside** the [`chcekdown` package](",
           hint_title = "Click he`R`e")
Click heRe
check_question(answer = 4, 
               wrong = "a**R**e you su**R**e?", 
               right = "### `R`ight")

There is also a function for multiple hints:

check_hints(hint_text = c("look into the hint 2", "look into the hint 1"),
            hint_title = c("hint 1", "hint 2"), 
            list_title = "list of hints")
list of hints
hint 1
hint 2

It is worth mentioning that \n will be removed from hint_text and hint_title arguments, so in case you want to have a new line use html tag <br>.

check_hint(hint_text = "this<br>is<br>a<br>multiline<br>sentence")
Click here to see/close the hint

2. Inserting images

Sometimes it is nice to use images as a question. It also could be useful to insert images in hints. In order to do it you need to use insert_images() function, and enumerate the correct answer.

check_question(answer = 3, 
               type = "radio",
               options = insert_images(c("windows.png", 
                                       image_width = 30))

Arguments image_width and image_height also except vector of values in case you need different size for different pictures.

In case you want to use pictures within hints, it is better to use markdown markup for it:

check_hint("Here is a map: <br>

3. Some important notes

## [1] -0.2876821
check_question(answer = round(log(3/4), 5), placeholder = "0.12345")