Is it really completely random? I only ask because recently i've been seeing my own face grinning at me far more often any of the other pics. I'm talking a good 60% of the time over the past couple of weeks. Is this just an odd co-incidence?

Quickly checking the code showing it uses array_rand, which means it should be random.

However I've also had certain pictures coming up far more frequently, and don't believe it is producing true randomness (where no image can be more likely to appear than any other).
If I could be bothered I'd write a script that hit the page every sixty seconds and recorded who it displayed and then did stats stuff to provide an answer.

The Law of 23s

Maybe.

But that wouldn't help prove if it's random?


It's perfectly plausible for 1 picture to appear more often than another over a set time period, each time the random bit is done it has no knowledge of, and is not influenced by, any previous page load. In other words just because an image loaded one time doesn't mean that that image is less likey to be picked the next time.

I'm sure you know all this, sorry if it sounds patronising and that.

I do know all that, but the experiment would still be a valid indicator.

Reduce it down to six pictures and decide them based on a dice roll - a fair die would give each number 16.7% of the time, so if you rolled the dice a few times and 1 & 6 each came up 40% of the time, whilst 2,3,4,5 come up 5% each, it's probably a weighted die, and whilst it might be unpredictable it's not random.

Of course to get accurate percentages you'd have to roll enough times - doing six rolls and expecting to get each picture once wouldn't be fair. Six hundred rolls and expecting a hundred (give or take twenty) would be better.

But we're talking about it being random, not fair.

Even over a million rolls it's perfectly possible for any one number to come up a hugely dispaportionate number of times. It may not be likely, but that's a different thing again.

Theoretically, yeah. But if that happened you wouldn't use that die as a means to selecting items that you wanted to appear 'randomly'.

Depends on your expectations ofvrandomness, really.

Fish.

*giggles*