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Author: Giovanni Marano

Bayes… Who? An Alternative Approach to Statistical Testing

18/04/2025 /

Imagine starting a new job and having to drive to the office on your first day. You’ve never been there before, but you know it’s next to a gym you used to go to. From experience, you remember that it typically takes about 30 minutes to get to the gym at that time of day — even though the last time you went was over a year ago (you eventually stopped going, but that’s another story).

Now it’s your first day on the job, and you need to decide what time to leave the house. Let’s imagine you don’t have access to GPS or navigation data. What would you do?

  1. Use the information you already have (even if it’s outdated) and plan for a 30-minute drive?
  2. Or ignore everything you know and randomly pick a departure time?

Naturally, the first option makes more sense — you’d rely on the information you have rather than ignore it completely.

Well, if that reasoning makes sense to you, then you’re already on your way to understanding a Bayesian approach to statistics.

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The Misleading Power of Correlation

13/12/2016 /

Have you ever heard a phrase like this? “A new Nicholas Cage movie just came out, so the number of people who drown in swimming pools is about to rise.” Probably not, and if you did hear it from a friend… well, you might have asked yourself a few questions about their mental state. However, looking at the graph below – based on real data – your friend might actually be right.

grafico-correlazione
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The useleness of absolute numbers

26/05/2016 /

A few days ago, I was reading an article about accidents involving cyclists. Being an avid cyclist and dealing with data and numbers of all kinds every day, I immediately noticed this sentence: “The regions most affected by accidents are those where bicycles are a real tradition: Lombardy, Veneto, Emilia Romagna, and Tuscany. Incidents tend to occur on Saturdays and Sundays, between 10 AM and 12 PM, during the months of May to October, with a peak in August.”

What seems odd to you?

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Don’t trust the latecomers

15/01/2016 /

When creating a blog, one of the first things to do is to come up with a name. Before choosing datastory.it, we considered several options, but some of them were already taken. On one of these sites, we came across a phrase that made our few remaining hairs stand on end. It went something like this:
“This site contains an algorithm capable of generating Lotto numbers that are more likely to be drawn than others.”

Such words sound to a statistician like a blasphemy sounds to a priest. Have you ever heard of “hot numbers” or “overdue numbers”? Surely you have. Well, we can guarantee you that these numbers are meaningless, and there is no algorithm capable of generating numbers more likely to be drawn than others. Let’s explore why.

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The Sad Story of the Inductivist Turkey

26/11/2015 /

It’s Christmas dinner, an allegory of abundance and a stage for opulence. Your neighbor at the table, probably a fourth cousin whose name you barely remember, is starting to show signs of giving up and is desperately seeking your complicit gaze. But with feigned nonchalance and reckless boldness, you act as if you’re still hungry, even though the amount of food you’ve just consumed could satisfy the caloric needs of the entire province of Isernia. Then, as the third hour of dinner strikes, a new, succulent course is brought out: a stuffed turkey.

At that moment, in a fleeting pang of consciousness – typically left at home during such occasions (otherwise, how else could one explain such an absurd amount of food?) – you wonder about the story behind the turkey in front of you.

This turkey lived on a farm where, from day one, it was fed regularly. The turkey noticed that food was brought every day at the same time, regardless of the season, weather, or other external factors.

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