chatGPT visualisation

openAI published a working paper on how people use chatGPT. They include a visualisation that triggered my curiosity.

The width of the columns represents the cumulative proportion of the main category, and the height of each sub-category represents the proportion of the sub-category within the main category.

The first problem is that the percentages of the main categories do not add up to 100.

Main CategoryPercentage
Multimedia6.00
Other / Unknown4.60
Practical Guidance28.30
Seeking Information21.30
Self-Expression4.30
Technical Help7.50
Writing28.10
Grand Total100.10

The percentages of the sub-categories, however, do add up to 100. Next, I measured the width of the columns to test if they actually got it right.

I then (ironically) used chatGPT to extract the numerical values from the graph.

Next, I divided the width of the column by the percentage it is supposed to represent.

Main CategoryCalculated PercentageColumn WidthColumn Width Ratio
Multimedia5.943.07.3
Other / Unknown4.532.57.2
Practical Guidance28.3208.57.4
Seeking Information21.3157.07.4
Self-Expression4.330.07.0
Technical Help7.654.07.1
Writing28.1207.57.4

While the columns approximate the main category percentages, they vary considerably. So, how can we do this better? The answer is a good old area graph. It scales each box according the the percentage and groups them into the main categories by color.

A new type of visualization is not always a better visualization.

Book Launch Event

We are delighted to invite you to the launch of Swim Training Patterns: Plan your Training Sessions with the Power of Mathematics by Christoph Bartneck, published by Routledge.

Event Details

Date: Wednesday, November 5th, 2025
Time: 5:30 pm
Venue: University Book Shop, University of Canterbury
Map: https://maps.app.goo.gl/zLsx55xFePJVmu33A

This exciting new book explores how mathematics can be used to structure effective and engaging swim training sessions, offering fresh perspectives for coaches, athletes, and anyone passionate about swimming.
Join us to celebrate the release, hear insights from the author, and enjoy an opportunity to connect with fellow swimmers, coaches, and academics.

Drinks and finger food will be served. Copies of the book will be available for purchase and signing. We look forward to seeing you at the University Book Shop to celebrate this special occasion.

Breaking Math Interview

I had the pleasure of talking to Autumn at the Breaking Math podcast about Swim Training Patterns. You can also listen to the interview at Spotify and other podcast platforms. I am grateful for her praise: “An awesome book with amazing art and graphs that’s accessible for anybody, whether you are a mathematician, computer scientist or anyone who wants to learn more about swimming.”

Interview with SwimSwam

I had the pleasure of talking to Coleman Hodges from the SwimSwam Podcast about my new book “Swim Training Patterns“.  Coleman had some very interesting questions. I was particularly interested in his description of reputations. He called them “sacred”. Which highlights the special status they have in swimming. We would not want to swim a repetition that would be 2x, 4x, 6x, 7x. It has to be 8x.

Custom Book Casing

Today I created the custom book casings for my upcoming book “Swim Training Patterns“. Getting the settings for the laser cutter right was pretty difficult. You want clear marks on the cardboard, but you don’t want to burn all the way through. A fun little project for my upcoming Traveling Book Project.