@Bumblefish

Which one is random?
(data sets are 100 numbers 1 to 6)

listA=[2,3,5,1,2,2,4,2,4,5,2,3,3,4,5,6,4,2,6,2,2,1,3,4,5,5,6,3,3,6,1,4,2,1,4,5,2,2,3,3,3,5,6,3,2,4,5,5,1,1,1,6,1,4,3,5,5,3,1,1,1,6,1,4,6,6,3,6,6,2,4,4,4,5,1,5,6,2,6,1,1,2,4,2,2,3,4,4,5,6,1,3,3,3,5,4,6,5,1,6]

listB=[4,2,5,6,3,5,3,1,3,4,2,3,4,3,4,5,5,1,3,3,2,1,1,6,1,3,2,2,2,6,1,5,6,3,6,3,2,3,2,4,6,1,1,6,3,2,4,1,6,1,3,1,5,6,2,3,3,5,1,6,4,5,2,5,1,1,5,3,6,2,3,3,6,5,2,3,3,1,6,3,2,3,2,1,6,6,4,4,6,2,4,5,4,5,3,4,6,5,3,2]

@futurebird @Bumblefish The only way you could determine that something’s not random is if a pattern emerges in the data set. Even still, statistically, it is probable for a CSPRNG with good entropy to produce a random data set that looks like it’s not random—unlikely, but probable.

@ramsey @Bumblefish

Only one of these lists could *plausibly* be from rolling dice.

@futurebird @Bumblefish Based on the statistical distribution of the dice rolls?

@futurebird @ramsey @Bumblefish this is not remotely my area of expertise but I am interested in the answer. My guess would be that the list that looks more evenly distributed is the fake one, and therefore List A is the "actually random" one because it has more seemingly outlying subsets, like a whole bunch of 1s in rapid succession.

There are tons of ways to unevenly distribute but relatively few ways to evenly distribute, so the one that seems less even is more likely to be true

@futurebird @ramsey @Bumblefish also I suspect maybe a Monty Hall kind of thing where you generated a bunch of random lists, and then selected the one that looked least random to you to trick your students.

I'd love to know what the actual answer is and what you were hoping to teach your students!

@ldpm @ramsey @Bumblefish

I put the answer in the original thread with a CW. This was about frequency.

@futurebird @Bumblefish I have a UUID-generating library that, under certain conditions, could generate the same identical UUIDs because the CSPRNG it used ended up reusing the same entropy seed, unless the server was restarted. That was a *fun* bug to investigate and fix. 😉