How Random is your iPod's Shuffle?
How many times have you set either your iPod or iTunes to "shuffle" mode only to be confronted by a very familiar sequence of songs? For me this happens all to often.
At work I connect my 5G iPod into my Powerbook and play my music directly through iTunes. I do this every day I'm at work and almost always have iTunes set to "shuffle" my entire iPod Library. Now I have around 5000 loaded up yet why on earth do the same 50 or so always play in the first hour of shuffling? Today was exceptionally non random! I listened to about 1.5 hours worth in the morning, disconnected my iPod then plugged it back in to continue listening at lunch. To my surprise the "random" selection of songs from my 5000 strong library was remarkably similar to the selection I heard in the morning! You could say around 70% of the tracks played I had already heard that day.
Now am I going crazy here? Surely I'm not the only person to experience this strange phenomenon of selective randomness. It certainly feels as though certain tracks in my Library always magically get selected out of the pack in the first hour!
Stephen Levy Tackles the issue directly and quizes an Apple Engineer and a University Professor about the mystery of the selective iPod.
It's quite common for random processes (like coin tosses) to get unlikely results here and there, like runs of six heads in a row. Over a very long time, it evens out, but it's hard for us to envision that. "We often interpret and impose patterns on random processes," he says, adding that this might be expected in th e case of music, which evokes strong emotions. Paul Kocher, president of Cryptography Research, puts it another way: "Our brains aren't wired to understand randomness."
The above passage got me thinking about quantum mechanics and the effect of observation on an experiment. Is it possible that our simple observation of a random event (such as the selection of a song in iTunes Shuffle mode) can have a direct effect on its outcome?
Comments
mmm. Seems like an interesting theory. Shuffle always seemed a bit dodgy to me. Tried the smart shuffle slider in your preferences panel? I mean sliding it towards less like isn't truly random anymore but at least you will get a little more variation going. Or it could be an issue with shuffling an external music device via iTunes! The theories are endless.
Not only does my iPod not seem very random, my car's Pioneer WMA/MP3 player's "random" setting isnt very random either. Or at least, that's how it seems.
This phenomenon will be seen even with small numbers of plays.
As a trial, load some manageable number of songs (say, 50), and keep a tally. You would not expect songs to come up 1 time in 50 consistently, some would be freakishly higher, some lower. After 5000 plays the expectation value for a song would be 100 plays, plus or minus 10 (with wings, so some would be played more often, some less, I think it's about 70% in the plus or minus 10, with about 90% in plus or minus 20.)
For the small number of plays you do each day, the expected variation is greater. With 450 plays you'd expect to hear each song 9 times, plus or minus 3, that's a rise from a 10% variation to a 33% variation, and you'd expect to hear roughly 10% of the songs 15 times, and about 3% of them 18 times., and that's assuming real random numbers
Caveat: The percentages are from memory, but I think they're roughly okay.