Bloggers swallow iPhone 4 screen weakness claim
Display damage data not as transparent as they seem
Analysis You have to take care with statistics, and that is certainly the case with the report  from US computer warranty house SquareTrade headlined "iPhone 4 glass breaking 82 per cent more than iPhone 3GS four months in".
Says the company: "SquareTrade analysed iPhone accidents for over 20,000 iPhone 4s covered by SquareTrade Care Plans and found a [sic] 82 per cent increase in reported broken screens compared to the iPhone 3GS."
According to SquareTrade, its numbers show that of the accidental damage suffered by the iPhone 4, 82 per cent of the breaks reported to the company centred on the screen, while 17 per cent were "liquid damage", leaving every other cause to amount to just one percentage point.
For the 3GS, the last two types rise to four per cent (other) and 20 per cent (liquid). Screen damage was cited in 76 per cent of incidents.
SquareTrade sampled 20,000 iPhone 4 owners who have taken out its extended warranty, and 20,000 iPhone 3GS owners who did the same. Its numbers show there were 940 iPhone 4 accident claims and 560 iPhone 3GS claims. Those totals yield 427 iPhone 3GS broken-screen claims and 771 iPhone 4s said to have the same problem, and that's indeed around 82 per cent more.
Now, that the vast majority of claims made against SquareTrade warranties centres on the handset's screen shouldn't surprise anyone - it's the weakest point in any touchscreen phone.
But bear in mind that the iPhone 4 has two glass panels, significantly increasing the chance that, if you have butter fingers, one panel, either front or back, will break when you drop it. And don't forget we're tracking accidents - user failures, if you will - not inherent hardware failures, which we'll come to shortly.
SquareTrade says that "at least a quarter of the broken glass claims involved the back screen". Crunch the numbers, and that's 193 incidents out of 771 broken-glass iPhone 4s recorded by SquareTrade. Obviously, only around 75 per cent of iPhone 4 front screens were reported as damaged, which is close enough to the 3GS score (76 per cent) as to make no odds.
In fact, you can argue that because the iPhone 4 claims haven't demonstrated a 100 per cent increase in broken-glass claims despite the presence of a second glass panel - a 100 per cent increase in the handset's glass area - that the aluminosilicate in the iPhone 4 is actually more resilient than the screen in the 3GS.
Looking at SquareTrade's numbers for overall failure rates, we find that the company admits that "fewer than 0.5 per cent of iPhone 4 owners reported a non-accident claim, roughly the same as the iPhone 3GS". That's a rate, SquareTrade says, is "much lower than most other consumer electronics". Since some folk will inevitable try and hide accidental damage as inherent hardware failure, the figure is probably lower still.
Those are our italics in the quote above, because they highlight that the iPhone 4 is not, of itself, any more likely to fail than its predecessor.
The difference between the two is purely down to accidental damage, and since we have no way of determining how casually the claimants tossed their new handsets around - or not - it's impossible to justifiably claim - as some reporters appear to be doing - that the iPhone 4 is somehow less reliable than the iPhone 3GS.
No. Fail to take good care of it and, yes, one or both of its glass panels is more likely to break than the one on the 3GS was. But look after your iPhone 4 and it's no more likely to break than its predecessor.
That doesn't get Apple entirely off the hook. The iPhone 4, with a glass back as well a glass front, has a lower coefficient of friction than its predecessor. No matter what handset you own, you'll invariably place it face up when you put it down on, say, a sofa arm. It takes a lot less force to send a 4 sliding off than it does a 3GS unless you keep it in a case. This reporter knows this for a fact, from his experience of both handsets.
Apple's two-glass design for the iPhone 4 does make accidents more likely, but nothing which more careful ownership can't accomodate without changing how you hold or place the handset. ®