Martin Krzywinski / Canada's Michael Smith Genome Sciences Centre / mkweb.bcgsc.ca Martin Krzywinski / Canada's Michael Smith Genome Sciences Centre / mkweb.bcgsc.ca - contact me Martin Krzywinski / Canada's Michael Smith Genome Sciences Centre / mkweb.bcgsc.ca on Twitter Martin Krzywinski / Canada's Michael Smith Genome Sciences Centre / mkweb.bcgsc.ca - Lumondo Photography Martin Krzywinski / Canada's Michael Smith Genome Sciences Centre / mkweb.bcgsc.ca - Pi Art Martin Krzywinski / Canada's Michael Smith Genome Sciences Centre / mkweb.bcgsc.ca - Hilbertonians - Creatures on the Hilbert CurveMartin Krzywinski / Canada's Michael Smith Genome Sciences Centre / mkweb.bcgsc.ca - Pi Day 2020 - Piku
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posters: primary


Scientific graphical abstracts — design guidelines


data visualization + design
POSTER HOSPITAL
If you're interested in posters and creating data stories, ready my Effective Poster Design for Science Communication, which shows many redesign examples. Download the handy poster template that's also a poster about making posters.

"This figure might give you a migrane"

What happens when a friend sends me a bad figure

Sometimes, I get emails that look like this

   Sent: Monday, July 29, 2019 at 07:59
   From: Jasleen Grewal
Subject: This figure may give you a migrane

As you can see, 100% of the graphs are ineffective.
BMI and prevalence for 185 countries by Martin Krzywinski / Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Each ring plot shows the fraction of population with a BMI ≥ 25 in a country. A page from Atlas der Globaliesierung: Welt in Bewegung, by Stefan Mahike (2019)

Here, I wanted to take you through my reaction to the figure, which was quick, and the redesign, which wasn't quick.

text labels — it's a hard life

I'm always on the lookout for abused text. So here I cried. A lot.

BMI and prevalence for 185 countries by Martin Krzywinski / Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
A large fraction of labels either barely fit or don't fit. Some are hyphenated and some of those still don't fit. A page from Atlas der Globaliesierung: Welt in Bewegung, by Stefan Mahike (2019)

strangely structured legend

Do we really need a footnote inside the legend? The globe? The hyphenated "Body-Mass-Index". By this point, I really could feel that migrane.

BMI and prevalence for 185 countries by Martin Krzywinski / Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
For a simple encoding, the legend is quite complex. From a page from Atlas der Globaliesierung: Welt in Bewegung, by Stefan Mahike (2019)

here's the graphic — now what?

What question's does this figure answer? Here's my list, with answers.

1. How many countries are there in the world? A lot.

2. What is the range of BMI ≥ 25 prevalence? 18—89.

3. Who has the lowest and highest prevalence? Vietnam and Nauru.

4. What is the median prevalence? Probably 55 and answering this is only made easy by the fact that the book's spine splits the plot into largely two equal halves

5. What is the prevalence where I live (e.g. Canada)? I gave up trying to find "Kanada".

Essentially, the two-page figure of ring charts is equivalent to the summary

BMI and prevalence for 185 countries by Martin Krzywinski / Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
This figure answers the same questions as the two-page spread for all but the most patient.

critique by redesign

It's obvious what's wrong with the figure. How do you fix it?

Using the list of countries by body mass index, I created a poster that tells interesting stories about how high BMI and obesity vary across countries and genders.

I describe the design and stories in the poster in the design section.

BMI and prevalence for 185 countries by Martin Krzywinski / Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
My redesign of the original figure showing preBMI ≥ 25 and obesity prevalence in 185 countries.

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news + thoughts

Music for the Moon: Flunk's 'Down Here / Moon Above'

Sat 29-05-2021

The Sanctuary Project is a Lunar vault of science and art. It includes two fully sequenced human genomes, sequenced and assembled by us at Canada's Michael Smith Genome Sciences Centre.

The first disc includes a song composed by Flunk for the (eventual) trip to the Moon.

But how do you send sound to space? I describe the inspiration, process and art behind the work.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
The song 'Down Here / Moon Above' from Flunk's new album History of Everything Ever is our song for space. It appears on the Sanctuary genome discs, which aim to send two fully sequenced human genomes to the Moon. (more)

Browse the genome discs.

Happy 2021 `\pi` Day—
A forest of digits

Sun 14-03-2021

Celebrate `\pi` Day (March 14th) and finally see the digits through the forest.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
The 26th tree in the digit forest of `\pi`. Why is there a flower on the ground?. (details)

This year is full of botanical whimsy. A Lindenmayer system forest – deterministic but always changing. Feel free to stop and pick the flowers from the ground.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
The first 46 digits of `\pi` in 8 trees. There are so many more. (details)

And things can get crazy in the forest.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
A forest of the digits of '\pi`, by ecosystem. (details)

Check out art from previous years: 2013 `\pi` Day and 2014 `\pi` Day, 2015 `\pi` Day, 2016 `\pi` Day, 2017 `\pi` Day, 2018 `\pi` Day and 2019 `\pi` Day.

Testing for rare conditions

Sun 30-05-2021

All that glitters is not gold. —W. Shakespeare

The sensitivity and specificity of a test do not necessarily correspond to its error rate. This becomes critically important when testing for a rare condition — a test with 99% sensitivity and specificity has an even chance of being wrong when the condition prevalence is 1%.

We discuss the positive predictive value (PPV) and how practices such as screen can increase it.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Nature Methods Points of Significance column: Testing for rare conditions. (read)

Altman, N. & Krzywinski, M. (2021) Points of significance: Testing for rare conditions. Nature Methods 18:224–225.

Standardization fallacy

Tue 09-02-2021

We demand rigidly defined areas of doubt and uncertainty! —D. Adams

A popular notion about experiments is that it's good to keep variability in subjects low to limit the influence of confounding factors. This is called standardization.

Unfortunately, although standardization increases power, it can induce unrealistically low variability and lead to results that do not generalize to the population of interest. And, in fact, may be irreproducible.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Nature Methods Points of Significance column: Standardization fallacy. (read)

Not paying attention to these details and thinking (or hoping) that standardization is always good is the "standardization fallacy". In this column, we look at how standardization can be balanced with heterogenization to avoid this thorny issue.

Voelkl, B., Würbel, H., Krzywinski, M. & Altman, N. (2021) Points of significance: Standardization fallacy. Nature Methods 18:5–6.

Graphical Abstract Design Guidelines

Fri 13-11-2020

Clear, concise, legible and compelling.

Making a scientific graphical abstract? Refer to my practical design guidelines and redesign examples to improve organization, design and clarity of your graphical abstracts.

Martin Krzywinski @MKrzywinski mkweb.bcgsc.ca
Graphical Abstract Design Guidelines — Clear, concise, legible and compelling.