Web exercises with webexercises

webexercises has replaced webex and is on CRAN

Dale and Lisa are developing an R package called webex to make it easier to make web-based exercises. It provides an RMarkdown template and a few functions to make questions that automatically give feedback and hint or solution buttons.

Create fill-in-the-blank questions using fitb(4), providing the answer as the first argument.

• 2 + 2 is

You can also create these questions dynamically, using variables from your R session.

x <- sample(2:8, 1)
fitb(x)

• The square root of 16 is:

The blanks are case-sensitive; if you don’t care about case, use the argument ignore_case = TRUE.

fitb("E", ignore_case = TRUE)

• What is the letter after D?

You can set more than one possible correct answer by setting the answers as a vector.

fitb(c("A", "E", "I", "O" , "U"), ignore_case = TRUE)

• Type a vowel:

If you want to ignore differences in whitespace use, use the argument ignore_ws = TRUE and include spaces in your answer anywhere they could be acceptable. Note, you need to escape double quotes inside of a quoted string using a backslash like this: "I am using \"quotes\" in my quoted string".

answers <- c(
  "library( tidyverse )", 
  "library( \"tidyverse\" )"
)
fitb(answers, ignore_case = TRUE, width = "20")

• How do you load the tidyverse package?

Create multiple choice questions using mcq(c(answer = "correct answer", "incorrect 1", "incorrect 2")).

lyrics <- c(
  answer = "let you down", 
  "let you go", 
  "turn you down", 
  "run away"
)
mcq(lyrics)

• “Never gonna give you up, never gonna: let you downlet you goturn you downrun away”

• “I left the reignsbless the rainsguess it rainssense the rainbless the waves down in Africa” –Toto

If your options are just true or false, you can make a quick MCQ with torf(TRUE) or torf(FALSE)

• You can permute values in a vector using sample(). TRUEFALSE

Webex also lets you make hidden solutions and hints by surrounding the hint or answer with hide("Button Text") and unhide().

• Recreate the scatterplot below, using the built-in cars dataset.

## `geom_smooth()` using formula 'y ~ x'

I need a hint

?geom_smooth

Solution

ggplot(cars, aes(speed, dist)) +
  geom_point() +
  geom_smooth(method = "lm", color = "red") +
  ylab("distance")

Getting Started

1. Install webex from github. This is a little different from typical installation, since the package is in development. Just use the code below.

devtools::install_github("dalejbarr/webex")

2. Create a new RMarkdown file

3. Select the “Web Exercises” template.

4. Edit the template with your content. Leave the setup chunk of code at the top.

5. Knit to HTML

6. Open the new .html file in your web browser.

You can publish your html files on any web server, or set up a website on github using our instructions for creating an academic website.