How to start with `checkdown`

George Moroz

2020-04-03

Instalation

Get the stable version from CRAN:

install.packages("checkdown")

… or get the development version from GitHub:

install.packages("devtools")
devtools::install_github("agricolamz/checkdown")

1. Demo

The main goal of this package to create checking fields and boxes in rmarkdown. It could be used in class, when teacher share materials and tasks, so student can solve some problems and check themselves. 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 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 intaractive autochecking tasks. The interactive virsion 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:

library(checkdown)

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 with the chunck atribute results='asis' 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")

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"))

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 = TRUE)

You can shuffle answers using the random_answer_order argument:

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

1.2 Give some hints with the `check_hint()` function

Sometimes you now in advance what kind of mistakes will your students do. Some students are shy and don’t like ask 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:

check_hint("You can use the rmarkdown package",
           click_text = "CLICK HERE")

CLICK HERE

It is possible to use Markdown inside messages:

check_hint("* You can use the **`rmarkdown` package**",
           click_text = "Click he`R`e")

Click heRe

check_question(answer =  4, 
               wrong = "a**R**e you su**R**e", 
               right = "### `R`ight")

2. Some important notes

It is possible to avoid code in the output .html. Just use the chunk argument echo=FALSE.
For now the package checkdown works only with html output and will not print anything for other otputs.
Be careful with number precision: rounding could be different on different computers so if you ask your student to calculate log(3/4) it is possible that they will see only 6 or 7 numbers after the comma. So it make sence explicitly specify precision using round() function.

log(3/4)

[1] -0.2876821

check_question(answer =  round(log(3/4), 6))

How to start with checkdown