Click the Original, Code and Reconstruction tabs to read about the issues and how they were fixed.

Original


Source: Moreton Bay Koala Rescue (2022).


Objective

The purpose of this visualisation was to demonstrate the increase in Koala sickness in recent years, with a target audience of the Moreton Bay Region public, from interested citizens, environmental activists or academics.

The visualisation chosen had the following three main issues:

  • Deceptive: There has been an error in the way the data source was prepared for this visualisation. It appears as though, in an effort to account for the fact that the data source did not include a full year of data for 2020, the creator has attempted a linear projection by multiplying the figures by 4, without also multiplying the total by 4. This resulted in the percentages for 2020 being far too high.
  • Preattentive Processing - Positioning: The visualisation features a large red arrow which is attempting to highlight the “Increase in sick koalas”, but is pointing to the bar for the increase in ‘Sightings’.
  • Red-Green Colour Blindness: Out of consideration for the percentage of the target audience that may be colour blind, the red and green bars should not be immediately adjacent.

Reference

Code

The following code was used to fix the issues identified in the original.

library(ggplot2)
library(RColorBrewer)
library(magrittr)
data <- read.csv("SourceData.csv")
newHeadings <- c("Record","Year", "Percent")
colnames(data) <- newHeadings
data[,1]<- factor(data[,1], levels = c("Sightings","Sick","Hit By Car", "Dog Attack", "Other"))
data[,2]<- factor(data[,2], levels = c("2009","2010","2011","2012","2013","2014","2015","2016","2017","2018","2019","2020*"))
data2 <- data[data$Record == 'Sick',]


p1 <-ggplot(data, aes(x=Year, y=Percent, fill= Record )) + 
  geom_bar( stat="identity", position = position_dodge(), width = 0.7)+
  geom_line(data=data2,linetype = "dashed", color = "orange3", aes(x=Year, y=Percent, group=1, color=Record, label = "Sick Trend" ))+
  scale_fill_brewer(palette="Set2")+
  labs(title="Koala Callouts \n 2009-2020",
       x= "Year",
       y= "Percent of Koala Records")

Data Reference


Source: Moreton Bay Koala Rescue (2022).


Reconstruction

The following plot fixes the main issues in the original.