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

Original


Source: Block, R. (2008).



It is the photo taken from Macworld in 2008, which Steve Jobs used this pie chart to share the news that iPhone became popular in the US market.



Objective

The 3D pie chart is used by Steve Jobs at Macworld 2008 keynote. This diagram presents the market share of smartphones by different brands at that time in the United States 2008. It aims to show that the iPhone 3G had a great market share compared to other smartphones. The target audience is technology media that would introduce the iPhone to the potential buyers who are interested in switching to Apple, or retailer companies that would have interest to sell it. According to the diagram, the iPhone becomes the 3rd place in the market in 2008, it persuades buyers/retailers that the iPhone is a competitive product in the United States.

The visualisation chosen had the following three main issues:

  • Briefly explain issue 1

3D effect of the pie chart misleads the audience thinks that the iPhone is the 2nd place in the market share. The chart is tilted, which looks the bottom part of the chart is closer to the screen than the top, and it makes the proportion of the green seem to be bigger than the purple. It is no point to use the 3D effect in this case unless to fool the audience by visualizing.

  • Briefly explain issue 2

There are no labels of each category on the pie chart, only includes numbers. Audiences need to figure out each proportion stands for what products by looking at the legend. And also the pie chart itself could not show clearly comparison between each category. One reason is that the chart is the 3D version (mentioned above), and another reason is that the audience needs to compare the percentage by comparing the angles of each category. Since the graph wants to present that the iPhone is the 3rd place of the market share (19.5%) and the figure of the 2nd place is 21.2%, the angles are no much differences between these two numbers. Pie charts could be used to present a huge difference while it is not suitable for this case.

  • Briefly explain issue 3

Neither layout or colour scales in the pie chart shows the ordinal of market shares by different brands. The segment of the pie charts is not layout ascending/descending, and there are no colour scales in the pie charts to show the trending, even the legend is not sorted.



Reference



Code

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

library(ggplot2)

marketshare <- data.frame(brand = c('RIM', 'Apple', 'Palm', 'Motorola', 'Nokia', 'Other'),
                         index = c(39, 19.5, 9.8, 7.4, 3.1, 21.2))

p <- ggplot(data = marketshare, aes(x = reorder(brand, -index), y = index))

p <- p + geom_bar(stat = "identity", color = 'steelblue', fill = 'steelblue') + 
  theme_minimal() +
  geom_text(aes(label = index, vjust = -0.5)) +
  ggtitle("US smartphones of the market share 2008") +
  xlab("Brands") +
  ylab("MarketShare by %")

Data Reference

Reconstruction

The following plot fixes the main issues in the original.