Summary and Schedule

This lesson introduces ggplot2 for learners with basic R experience. It is designed as a short, focused session (approximately 2 hours).

The lesson assumes familiarity with the R language and the RStudio interface. It begins by introducing the grammar of graphics, which underpins how ggplot2 constructs plots. Using the built-in mpg dataset, learners will explore how to create different types of visualisations and how the choice of plot depends on the question being asked.

This lesson focuses on the fundamentals of data visualisation using ggplot2. While examples may reference how plots are used in statistical contexts, it does not cover statistical analysis.

Prerequisite

Participants should have completed an introductory R course (e.g. R for Reproducible Scientific Analysis or have equivalent experience. This includes familiarity with RStudio, running scripts, and working with data frames.

	Setup Instructions	Download files required for the lesson
Duration: 00h 00m	1. ggplot2 Essentials	How do I create plots with ggplot2? How do I save the plots I created?
Duration: 00h 30m	2. Explore Relationships	How can scatterplots be used to explore relationships between variables? How do aesthetic mappings and layers help reveal patterns in data?
Duration: 01h 00m	3. Understand Distributions	How can we explore a single variable in ggplot2? What does the shape of a variable’s distribution tell us? How can we compare distributions across groups?
Duration: 01h 30m	4. Compare Groups	How can we summarise a distribution? What key information helps us understand a distribution quickly? How can we compare these summaries across groups?
Duration: 02h 15m	5. Explore Composition	How can we show how data are divided into parts? What does each category contribute to the whole?
Duration: 03h 00m	6. Communicate Results	How can we make plots easier to interpret? When is it helpful to split a plot into multiple panels? How can labels improve communication?
Duration: 03h 35m	Finish

The actual schedule may vary slightly depending on the topics and exercises chosen by the instructor.

R and RStudio

This lesson assumes you have R and RStudio installed on your computer.

• Download and install the latest version of R.
• Download and install RStudio. RStudio is an application (an integrated development environment or IDE) that facilitates the use of R and offers a number of nice additional features. You will need the free Desktop version for your computer.

Required R packages

For this lesson we will use the package tidyverse.

The tidyverse is a beginner-friendly collection of R packages designed specifically for data science that share a unified design philosophy, grammar, and data structure. It simplifies data importing, cleaning, and manipulation, making R much more intuitive to learn and read.

R

install.packages("tidyverse")

ggplot2 is the premier data visualization package within the tidyverse, meaning it automatically loads when you call library(tidyverse) and seamlessly integrates with all other tools in the collection.

Check the package installed correctly by loading the ggplot2 library.

R

library(ggplot2)

Data

We will use the mpg dataset that is packaged with ggplot.

R

# View the dataset
head(mpg)

OUTPUT

# A tibble: 6 × 11
  manufacturer model displ  year   cyl trans      drv     cty   hwy fl    class
  <chr>        <chr> <dbl> <int> <int> <chr>      <chr> <int> <int> <chr> <chr>
1 audi         a4      1.8  1999     4 auto(l5)   f        18    29 p     compact
2 audi         a4      1.8  1999     4 manual(m5) f        21    29 p     compact
3 audi         a4      2    2008     4 manual(m6) f        20    31 p     compact
4 audi         a4      2    2008     4 auto(av)   f        21    30 p     compact
5 audi         a4      2.8  1999     6 auto(l5)   f        16    26 p     compact
6 audi         a4      2.8  1999     6 manual(m5) f        18    26 p     compact