Wald–Wolfowitz runs test
Imagine you have a bag of red and blue Legos. You want to know if the colors are evenly mixed, or if there are more of one color than the other. You can't count all the Legos, but you have a tool that lets you compare patterns in the bag to what you expect to see if the colors are evenly mixed.
The Wald-Wolfowitz runs test is kind of like that tool. Instead of Legos, it looks at a bunch of numbers (like test scores or heights) and tries to figure out if they're evenly spread out, or if there are clusters of high or low numbers.
The test looks at two things: the total number of "runs," or groups of consecutive numbers that are either all high or all low; and the size of the "expected runs," which is what you'd expect to see if the numbers are evenly spread out.
If the actual number of runs is close to what you'd expect based on chance, that's a good sign that the numbers are evenly mixed. But if you see a lot more long runs than you'd expect, or if there are big gaps between runs, that could be a sign that something weird is going on with the numbers.
The Wald-Wolfowitz runs test isn't foolproof, just like your Lego tool can't give you perfect information about what's in the bag. But it's a useful way to get a sense of whether a set of numbers is behaving the way you'd expect it to.
The Wald-Wolfowitz runs test is kind of like that tool. Instead of Legos, it looks at a bunch of numbers (like test scores or heights) and tries to figure out if they're evenly spread out, or if there are clusters of high or low numbers.
The test looks at two things: the total number of "runs," or groups of consecutive numbers that are either all high or all low; and the size of the "expected runs," which is what you'd expect to see if the numbers are evenly spread out.
If the actual number of runs is close to what you'd expect based on chance, that's a good sign that the numbers are evenly mixed. But if you see a lot more long runs than you'd expect, or if there are big gaps between runs, that could be a sign that something weird is going on with the numbers.
The Wald-Wolfowitz runs test isn't foolproof, just like your Lego tool can't give you perfect information about what's in the bag. But it's a useful way to get a sense of whether a set of numbers is behaving the way you'd expect it to.