90% of Statistics Are Irrelevant
Why statistical significance isn’t always that big of a deal
There’s a secret world you’ve probably never heard of. It lies underneath every claim you’ve ever read, every headline that has blared “science!” at you as you walked past. This world is why you’ve been vaccinated, why you take ibuprofen for pain and inflammation, and even why you can’t get contraceptive pills over the counter in most countries.
I’m talking, of course, about the world of statistics.
Studying Stats
Imagine you’re doing a study on weight loss. You’ve got, say, three groups of people: 1, 2, and 3. Group 1 is taking a drug. Group 2 is having a lifestyle intervention. Group 3 is a placebo control — they’re doing nothing. At the end of the study, you have hundreds, even thousands of numbers. You can compare them pretty easily — have a look at the means and medians — but all this really tells you is that there are some differences. They might be unimportant; they might be just down to chance. What if you had one person in Group 2 who started at 400 kilos and lost 300, but the rest of the people actually gained a couple kilos…