The Pareto principle (80/20)

Vilfredo Pareto, an Italian sociologist and economist, showed in his book Cours d'économie politique that 80% of the land in Italy is owned by 20% of the population. However, it turns out that this principle can be generalized to almost everything.

We get 80% of our produce from about 20% of our plants, 80% of a company's profit comes from 20% of its customers, and 80% of our grade in a subject comes from 20% of the material or even less. This rule also applies in more dramatic proportions, as it often happens that the rule also applies in proportions of 90/10, 95/5, or even 99/1! Therefore, just 1% of our invested effort can bring 99% of the results.

From our own experience, we have found that in college subjects, these numbers often range around 90/10. So, by knowing just 10% of the material, we can get a grade of 9 in college. How is this possible?

Exams, whether oral or written, only last for a short time (usually 1.5 hours). So, would you agree that if someone gave us the questions that we will get on the test, we could spend a fairly small amount of time learning them very well? And this is where the answer to our learning lies. Our task, our main task, if we want to be successful in our work, is to figure out which questions will be on the exam. Not literally, but we must focus on the key parts of the material that are most likely to be covered. Only then can we spend much less time for much better results.

So, before we even start learning, the key question is: What is most likely to be on the exam? We then start learning about these topics and slowly move towards less important ones. However, we must not stop there. Each of these topics also requires our thoughtful evaluation: What is 80/20 or even 90/10, so that I can say that I know enough about this topic for the exam?