Today I’m gonna talk about the Pareto principle (= 80/20 rule = the law of the vital few). The principle is named after Vilfredo Pareto, who stated that 80% of Italy was controlled by only 20% of its population.

#### What is it and how to apply

The law of the vital few is best interpreted as: ‘a small part of the input creates most of the result’. Once you understand this, it’s very easy to notice the ratio. In your day to day life for example. Like if I said that you only spend a small amount of time on the things that give you the most satisfaction, would you agree?

Let’s make one thing clear: the numbers don’t have to add up to 100%. It is just coincidental. The rule could have been 90/30. That would mean that 90% was influenced by only 30% of the population, for example. Actually… The exact numbers don’t matter. It’ll never be that exact ratio, yet it’s very usefull as a rule of thumb.

Using this principle, perhaps you need to rearrange your work method. Once you realize 20% of effort leads to 80% of growthyou realize that the beginning is hardest. Yet that doesn’t mean the rest of the effort is useless. On the contrary, the rest of the effort is necessary to perfect your work, though it doesn’t seem to make as much of a difference. This way of thinking makes it easier to differentiate the most important from the details. It let’s you focus on what gives the most output. A great example of this can be found on betterexplained.com.

#### Some examples:

• 20% of the employees are responsible for 80% of the output.
• 20% of customers make up 80% of sales.
• Even in sports: 20% of exercises and habits have 80% of the impact.
• 20% of hazards cause 80% of injuries.
• 20% of the roads have 80% of traffic.
• 20% of effort leads to 80% of growth.

#### 20% of a products functions are used 80% of the time

Let’s refrase that: 80% of the time only 20% of the functions are used. Can you think of an example? Open a Word document. Look at the user interface. Pay attention to what you see: a white page, a menu bar and a standard toolbar. Now, when you write, which functions do you use most, and how many clicks are they away?

When you realize that only 20% of the functions are used 80% of the time, you can make sure the user can easily get to these functions. When you want to insert a strange symbol in your Word document, you need to make more of an effort. Though, when you insert a formula and need a symbol, suddenly the most common ones are in your toolbar.

#### In conclusion

The Pareto Principle is definitely something to keep in mind when designing a product or user interface. A step on the way to make the user more comfortable. And thus, make the user like the product more.

What do you think? Do you agree with everything I said in this post? And can you think of other examples? -M