The elementary effects method is like when you want to know how different things affect something else, like baking a cake. Imagine you want to make a cake, but you don't know how much sugar, flour, or butter to use.
So, you decide to do a test - you make a little change to each ingredient to see how it affects the cake. You try a little more sugar, a little less flour, and a little more butter.
The elementary effects method is like that, but for more complex things, like a computer program. Instead of changing the ingredients of a cake, you change different parts of the computer program to see how each part affects the final result.
Scientists use this method to figure out which parts of the program are the most important and which ones they can change without affecting the result too much. It helps them see which parts of the program they need to focus on to make it work better.