ELI5: Explain Like I'm 5

Peirce's criterion

Alright kiddo, today we'll talk about something called 'Peirce's Criterion'. Do you remember learning about mean, median, and mode for finding the average of some numbers? Well, sometimes we want to find out if there are any unusual or extreme numbers in a set of data.

Peirce's Criterion helps us with that! It tells us if there are any 'outliers' in our data. Outliers are numbers that are very different from the other numbers in our data set. They can mess up our calculations and give us weird answers.

So, how does Peirce's Criterion work? First, we need to find the average of our data set. We call this the 'arithmetic mean'. Then, we look at each number in our data set and see how different it is from the mean. We do this by subtracting the mean from each number.

Now here's the important part - we take the absolute value of each of these differences. Do you remember what 'absolute value' means? It's when we ignore any minus signs and just look at the positive number.

We then put these absolute differences in order, from least to greatest. We call this our 'ordered set of absolute differences'.

Finally, we count how many numbers we have in our data set. Let's call that number 'n'. If the largest absolute difference in our ordered set is equal to or greater than the square root of (2/n), then that means we have an outlier in our data set.

Phew, that was a bit complicated, wasn't it? But don't worry, we just need to follow these steps and we'll know if there's an outlier in our data set or not. Keep learning, little one!