It's not a meaningful scientific basis for such a comparison. Choice of OS isn't a major factor in hardware quality. Nokia proves this; the N8 (Symbian), N9 (MeeGo), and Lumia 800 (WinPhone) are all of fairly similar quality (quite high, I might say); yet each runs a totally different operating system. Likewise, you can have two Android phones from different manufacturers (or even the same, in some cases) that are at very different extremes of hardware quality. A study such as [1] is far more meaningful, it's comparing manufacturer to manufacturer (the people responsible for putting the phones together) instead of OS to OS (as one phone could theoretically be sold with a different OS with no change in quality).

[1] http://www.squaretrade.com/pages/cell-phone-comparison-study...

I still don’t see why this is not a valid comparison. Sure, hardware is independent from software (more or less) but that doesn’t mean you can’t meaningfully compare the two.

It does mean you can't meaningfully compare the two.

Are you saying that if people started installing Android onto iPhones (if it were possible) all of a sudden the hardware failure rates for iPhones would sky rocket?

Of course not! Why would you think that?

All this says is that devices running Android fail on average more often than iPhones – for whatever reason (regression to the mean, one designer and manufacturer vs many, lower priced devices, and so on). That’s a perfectly valid comparison.

The comparison is invalid because iPhone/Blackberry devices are premium high cost devices with high quality control. A direct comparison will only work against other premium high cost devices with high quality control.

By comparing every Android phone on the market (from cheap to premium) to only premium devices you are always going to get a skewed result.

I don’t understand. Why does that make the comparison invalid? That makes no sense at all.

You are naming one factor that might explain the difference – but that is exactly the point of such comparisons! To figure out what the difference is!