How random is the iPod Shuffle?

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iPod Shuffle Problems: How Random is the iPod Shuffle?

So just how random is the shuffle capability on an iPod Shuffle? Even before the device debuted in 2005, people have wondered about the shuffle function on iPods. Many complain that what they hear from their MP3 players isn't random at all -- every time a new playlist is generated, the iPod seems to pick the same songs by the same artists from the same album. It's almost as though the iPod has its own favorite songs. It's started a flurry of debates in online forums, and some have even suggested that Apple has programmed iPods to play songs downloaded from the iTunes store more frequently than other songs. Apple has denied these claims [source: CNET].

One thing to keep in mind is that it's actually possible to set the degree of randomness. In the iTunes settings, you can choose to set the iPod to play "without repetitions," or you can make it play your favorite songs more frequently if you've rated them. Some people who may have starred their favorite artists and have the wr­ong settings selected are probably hearing Steely Dan over and over again for a reason.

Some argue that our brains are built to recognize order and patterns instead of chaos and randomness. It happens all the time. People like to find faces or animal shapes in the clouds or religious figures burnt on toast or marvel at the significance of a number -- anyone who watches the television show "Lost" might appreciate that last one.

We also have a hard time acknowledging certain coincidences. Take, for instance, the problem known as the birthday paradox. You'd think that after putting two people in a room, the chances of them having the same birthday would be extremely slim, right? You'd be right -- the chances are only 1/365, or 0.3 percent. But how many more people would you need to add to get that percentage up to 50 percent? Most people would say a lot -- when asked how many would need to squeeze into a room before one pair of similar birthdays popped up, university students gave a median of as many as 385 people [source: CompuServe].

The right answer? You only need 23 people to settle a birthday paradox bet with a coin toss. That number seems astonishingly low if we're talking about 365 days out of the year. Even though there may be as many as 500 different songs on an iPod Shuffle, you could think of an artist or an artist's album as a "shared birthday" for that group of songs. The chances of iTunes selecting several tracks from the same artist could be higher than we think, even if Apple's shuffle function does exactly what it's supposed to do.

Still, others argue that Steely Dan's "Reelin' in the Years" playing every other time is, in fact, not so random. To read more about iPods and MP3 technology, see the next page.