Chapter 8: Visualising Data
Links to a carefully curated collection of Youtube videos provide a host of additional sourcs for you to develop your ability to use R software in an engaging and accessible manner.
Video 8.1: ‘Learn R: an introduction to ggplot2’
Question 1: What is the difference between exploratory and explanatory data visualization?
Answer: Exploratory data visualization is easy to generate, data heavy, and intended for small specialized audiences. Explanatory data visualization are labor intensive, data specific, and intended for a broader audience; are more focused on visually communicating results.
Question 2: What is the benefit of looking at data visualization in addition to standard statistical analysis?
Answer: Because data visualization allows for a richer understanding of relationships beyond just the statistical numeri c outputs; as demonstrated by the Anscombe plots.
Video 8.2: ‘ggplot2 tutorial: Grammar of graphics’
Question 1: What are the two key principles of data graphics/visualizations?
Answer: Graphics are distinct layers of grammatical elements and meaningful plots are built around appropriate aesthetic mappings.
Question 2: What are the three essential elements of data graphics/visualizations?
Answer: The data, aesthetics, and geometries.
Video 8.3: ‘ggplot2 tutorial: ggplot2 layers’
Question 1: What is the fundamental understanding of how ggplot2 plots work?
Answer: That they are layers of grammatical elements.
Question 2: What is the first layer to a ggplot2 plot?
Answer: The data
Video 8.4: ‘Intro to data visualization with R & ggplot2’
Question 1: What is the ‘fill=’ option used for when creating a barplot with ggplot2?
Answer: It is used to plot a second categorical/factor variable, where this second variable appears as different colours in the barplot.
Question 2: What relationship does the box-and-whiskers plot not show that the other plots do show?
Answer: The box-and-whiskers plot really didn’t show that age mattered in survivability, but the other plots show that more children survived than didn’t survive.