As part of my own journey into Data Science, I wanted to read this book to understand what the pitfalls in data analysis could be, in order to not commit bullshit when that could be avoided.

Of bullshit

The book does an excellent job driving its reader through more and more perfid or subtle error introduced in a discource (from reporting to graphs etc), voluntarily or not. The section on percentages (which I have been using a lot at work without really giving a thought about it) is extremely interesting.

How could both things be true? Things get even weirder if we look at Uber’s contribution to this increase in rides. Uber provided an extra 383,000 rides per day by the end of this period. We could say that the increase in Uber rides is responsible for 130,000 / 108,000 × 100 = 120% of the increase in total rides. What does that even mean? How could the Uber increase account for more than 100 percent of the total increase?

This quote also stroke a chord in me as I sort of took refuge in numbers after a few years having to deal with wordy bullshit but have regular discussions with my partner as to whether numbers can really explain or describe a situation.

Words suggest intuition, feeling, and expressivity. But not numbers. Numbers suggest precision and imply a scientific approach. Numbers appear to have an existence separate from the humans reporting them.

Both can be manipulated. Both approaches can be correct. Both approaches can be bullshit.

The book also makes a point to explain the extended Hanlon’s Razor definition:

Never attribute to malice that which is adequately explained by stupidity but never attribute to stupidity which can be explained by inattention or ignorance

Calling bullshit

After going into great details into what constitute bullshit, the last chapter addresses Calling bullshit. What to do when you are confronted with a bullshit statement. Some of it is actually addressed in the different chapters and this chapter ties everything together while giving also behaviour recommandations (short version: don’t be an asshole, a concept some in the French zethetique community has a lot of difficulties to understand).

For the authors:

Effective bullshit calling is about making others smarter.

not for you to gain points. Or burn your counterpart.

Final word

Would I recommand this book? Yes, definitely. Even if you already know most of the pitfall described, I really liked the progression / book structure and approach.