Data Visualisation

Data Visualisation

In the psychsafety.com measurement workshop we cover a lot: research ethics, quantitative/qualitative approaches, longitudinal vs cross-sectional studies, formulating research questions, survey design, and communicating our findings. As part of that, we look at data visualisation, including this classic example: The Broad Street pump cholera map by John Snow in 1854.

From “On the Mode of Communication of Cholera” by John Snow, originally published in 1854.

A story well-known to all students of epidemiology, we covered this in depth last year in my master’s degree in global health. John Snow was an obstetrician and was a key figure in introducing anaesthesia to childbirth. He also believed, contrary to medical convention at the time, that cholera was water-borne, not airborne. In 1854, when an outbreak of cholera hit London’s Soho where Snow lived, he went to work to show that contaminated water was the cause, by plotting the locations of cases. He also investigated groups of local people who didn’t contract cholera, as he suspected this data would support his hypothesis. He found that a nearby prison had no cases of cholera, and it turned out that they had their own well from which they extracted drinking water. And as you can see in the map above, the brewery, just one block away from the broad street pump, suffered zero cases in their workers. Crucially, the fermentation process kills most pathogenic organisms in water, including cholera, so the employees of the brewery, who drank beer instead of water, were safe from the disease. There’s an important lesson there: beer is good for you.

In order to demonstrate his findings and prove the epidemiology of the cholera outbreak, John applied one of the earliest and now best-known data visualisations; he decided to plot each case on a map, using black bars to represent each death. The clustering of these bars around the Broad Street water pump provided an immediate visual insight: the water source was the probable epicentre of the outbreak. This led to an experiment: the removal of the pump handle and a subsequent decrease in cholera cases, proving Snow’s hypothesis that cholera was a waterborne disease. Further investigation showed that the original source of the disease was when a mother, whose baby had contracted cholera from a different source, had dumped a nappy into a leaking cesspool very close to the pump. 

What Snow’s map shows us is that raw data is valuable, but presenting it in an appropriate visual context can lead to breakthrough insights and resultant actions. Data visualisation isn’t just charts and graphs; it’s about narrating a story, illuminating patterns, and informing action.

Good data visualisations tell a story in a language that everyone can understand.

If you’re interested in data visualisation and communication, “The Truthful Art” by Alberto Cairo is a great start. Alberto Cairo describes the below interrelated qualities of a great data visualisation:

• Truthful. The data must be reliable, unobscured, unbiased and authentic.
• Functional. The visualisation should facilitate seeing relevant patterns. And it should be adapted to the audience, rather than making the audience adapt to the visualisation.
• Beautiful. It should be presented in an attractive manner, and one that engages the viewer.
• Insightful. A good visualisation should reveal trends, relationships and correlations clearly, and raise further questions for exploration.
• Exploratory. When appropriate and when possible, data visualisation should be organised in such a way that it enables exploration, for example by toggling variables to appear and disappear, zooming in, or broadening and narrowing the datasets.

Psychological safety at work

Here’s a great article by the fantastic Elizabeth Ayer, about how annual performance reviews ruin everything. I’m with Elizabeth on this one – in our management workshops, we often highlight the damaging aspects of the annual performance review: the terrible year-long feedback loop, the recency bias that means we focus on the successes and failures that happened most recently, the disproportionate way that performance reviews amplify existing biases, the way they force us to take a reductive and quantitative view of work, and the way they focus on individual success, undermining teamwork and increasing unhealthy competition. Unfortunately, many of us simply don’t have the power to change these practices in our organisations, but there are some things that we can do:

1. Advocate to drop them entirely.
2. Be candid with your team about how harmful they can be.
3. Implement your own, much tighter, growth feedback loops such as weekly 1-1s and 15/5s.
4. Strive to separate annual reviews from pay, promotions, and other rewards/opportunities.

Here’s a good little piece in OHS Canada by Julie Cafley and Sadaf Parvaiz, pointing out that when psychological safety is low, it can not only result in accidents but also reduce our ability to learn from accidents. If psychological safety is low, “leaders should question whether they even have an accurate accounting of incidents or potential job-site risks.”

I often see stuff on social media saying “Psychological safety is not ‘political correctness'”. And this is true, however: if we disregard people’s lived experiences, identities, pronouns, past trauma and existing structural inequities, we aren’t fostering psychological safety for everyone: only for those who are already privileged enough to not have to worry about those things.

We must recognise that it is not (yet) a level playing field, and it is not only morally right for us to address existing inequities, but it’s also the only way that we will truly realise the benefits of psychological safety in our organisations. We cannot disentangle work on psychological safety from work on inclusion: and that means acknowledging and addressing the challenges faced by minoritised and disadvantaged people.

Here’s yet another fabulous illustration by Lizz Fosslein showing the way that many of us diminish our successes and overthink our mistakes.

Amidst the clamour amongst some CEOs to get everyone back in the office, this is a refreshing take from Atlassian CEO Scott Farquhar: ‘Half our employees we’ve hired over the last few years couldn’t have come to work for us if we didn’t have that flexible working environment‘. Scott makes a number of good points, including that remote work:

• Means we can employ the best people for the job, not just those who live near one of our offices.
• Brings money into smaller towns and cities, rather than concentrating it into the few places where big corporations locate their offices.
• Allows more people to enter the jobs market who may have caring responsibilities or disabilities that prevent them from going to an office on a daily basis.
• Can foster new and interesting ways of collaborating in virtual spaces, and doesn’t preclude occasional, intentional, in-person collaboration.

This week’s poem:

The Two-Headed Calf, by Laura Gilpin

Tomorrow when the farm boys find this
freak of nature, they will wrap his body
in newspaper and carry him to the museum.

But tonight he is alive and in the north
field with his mother. It is a perfect
summer evening: the moon rising over
the orchard, the wind in the grass. And
as he stares into the sky, there are
twice as many stars as usual.