The August 2025 issue of Toastmaster magazine has two very useful
articles. One by Florian Bay on pages 20 to 23 is titled 5 Tips for Depicting
Data and subtitled How to use numbers and graphs to create a compelling story. His
five headings are:
Be Clear on Your Purpose
Select the Right Visual
Remove the Clutter
Engage with Colors but Don’t Create Rainbows
Use Text to Guide Your Viewers
The first two line and column bar charts, at the bottom of Page
20 are missing a label for the vertical axis, which should be Number of UNESCO
Sites. As shown above, I have added it in red.
Regarding pie charts, he says:
“Visualizing proportions? Then use a pie chart, but only if
you’ve got two or three slices to share; any more than that and the proportions
get hard to interpret. Stacked bar charts can also be useful.”
I don’t think pie charts ever are useful, as I discussed in
a blog post on September 16, 2008 titled Pie charts do not speak clearly; they
just mumble and one on July 29, 2022 titled Is there any excuse for using a pie
chart?
And his example with Yearly Passengers in London Heathrow
Airport 2005-2024 (shown above) has the numbers of years shown vertically
rather than horizontally. My Excel version omits the bullseyes around the
pandemic data and just shows numbers for all those data points. (On July 4, 2017
I blogged about Why is your audience tilting their heads sideways?)
The second article by Charlene Phua following on pages 24 and
25 is titled Make Your Data Presentations Come to Life and subtitled Avoid these
4 missteps to ensure your audience stays engaged. Her four headings are:
Including data that isn’t relevant to topic or audience
Having an inaccurate gauge of your audience’s understanding
Providing data with no context or comparison
Neglecting other aspects of your performance
For the third she uses the example of annual global carbon dioxide
emissions. She didn’t mention a number, but in 2022 they are 38,521,997,860
tons. We can ask What’s in it for me? The global Population is 8,021,407,192 people so it is 4.802 tons per capita,
or 9605 pounds. Per day it is 26.3 pounds, and converting that to a cube of dry
ice, it is one 7.75 inches on a side, as shown above.
On December 23, 2024 I blogged about How should we present a
huge number like the two billion dollars earned by the Taylor Swift Eras tour?
And on July 12, 2016 I blogged about How to make statistics understandable. Also,
on August 17, 2011 I posted on How to make a large number incomprehensible or
comprehensible and on July 15, 2011 I blogged on What can we say about a really
big hole in the ground?