Data lies to you (59)

Data never lies...

I am sure we have all heard that phrase before. It is especially common for it to pop up in arguments. You are discussing with a friend about a hot topic or perhaps its a business meeting and you are debating which supplier you will go with. That is where somebody wanting to reinforce their argument will show some data that reinforces his point and expect that this will change your mind too. After all, its science and science can't be wrong ... right?

People do lie

In fact, there are multiple ways such arguments could be much weaker in practice. First of all, the data itself might be wrong or biased. But even assuming you can trust the source, data without proper scaling is of little importance. Always pay attention to starting points of diagrams and the relative sizes of shapes, because while the data might be true, the visualization might be optimizing for storytelling.

Also good piece of advice: ask for anchor values. A sales number of €3 million might sound impressive, until you realize that the company deals with €1 million dollar products and has revenue of more than €3 billion. Put data into perspective

The magic is in the interpretation

But more importantly, data and science both are very good at giving us answers but not posing questions. We should always be aware of what question is being asked and what are the implications.

Here are three practical examples:

Our company makes two products. After analysis, it turns out the profitability per unit for product A is €100 and for product B its -€20. A "data based approach" might hint to ditching product B and going all in on A. But B might be a product that satisfied a customer so much that ends up giving us more deals of product A.
The ministry of health wants to pay doctors by their efficiency. In a remote hospital, there are 2 doctors with a mortality rate of 0.1% and 15%. Its tempting to say that the 0.1% doctor is better, but think of what is a doctor... Sometimes, they are forced to take on cases where the patient is in a bad shape because of age or smoking. A brave doctor that accepts all cases will thus inherently have a worse score, despite potential being a better doctor.
Considering the GDP of a modern country, power accounts to roughly 3%. Selling or losing that, wouldn't mean that the GDP of the country would fall only by 3% though, since all modern infrastructure and production relies on power. Hidden dependencies might obscure an otherwise clear data point/

In conclusion, while data may never "lie", it is still capable of hiding the truth. So ask better questions!

Comments

Easter feast and task pipelines (48)

A Greek Easter feast As this post goes live, your host and author is most likely indulging in the joys of Easter Sunday. In Greece, where I come from, Easter is the biggest holiday of the year. And, as you might expect from a culture famous for its love of food, the Sunday feast is a central part of the celebration. The meal varies by region and family tradition, but one thing remains constant: roasted lamb. It symbolizes the sacrifice of Jesus, and it's always the star of the table. If you're reading this on Easter Sunday, there’s a good chance I’m savoring some leftover lamb while you scroll through these lines. Now, let me tell you—preparing this feast is no small feat. Roasting the lamb and getting the rest of the meal ready is a coordinated effort, usually involving many helping hands. To make sure everything is done in time for the classic Greek lunch hour (around 14:00), the tasks must be broken down and distributed efficiently. This is where the real planning begins....

I think, therefore I am (35)

I think, therefore I am Consciousness—or self-awareness—feels like one of the most distinctly human traits. Sure, some animals are clever, but only a handful, like certain primates, seem to pass the “mirror test” and recognize themselves in their reflection. So, what exactly is consciousness? The truth is, it’s hard to pin down. Interestingly, an accessible definition of consciousness doesn’t come from philosophy or biology, but from medicine—specifically anesthesiology. In this field, consciousness is defined as the awareness of pain and our surroundings during surgery. It's a practical, measurable approach: you’re either aware or you’re not. This definition not only makes consciousness easier to grasp but also highlights its connection to our sensory perception. This view brings us to the classic "dual theory" of consciousness. In this framework, the body and mind are seen as separate entities, with the brain acting as the “control room.” The mind issues commands, the b...

A chess game played at a two hundred kilometers per hour (66)

A chess game played at a two hundred kilometers per hour That is how the sport of modern fencing is often portrayed by its practitioners, or, frankly, anyone with an inclination to dramatize. Often, in student fencing circles this phrase is used ironically to juxtapose how simple, pragmatic and brutal this sport can sometimes be. However, I am inclined to approach this phrase by visualizing its contents; fencing is indeed an ancient game, requiring wit and is supplemented with technology unimagined by previous generations. It really is a marriage cold calculation and passion. A passion which is shared by the previous blog exploring modern fencing technology, and which drives one to explore developments of fencing technology even deeper. How Horses Became Formula 1 A common passerby would not think of modern slender, antenna-like blades as swords. And they would be completely right, none of the three fencing weapons (saber, foil and epee) are swords. Assuming the sole purpose of a sword...

New Phaistos

Search This Blog