AppStart recently argued in favour of an iPad mini with a 7.85-inch screen, and the story is now doing the rounds on Mac rumour sites. Inevitably, they are using it to back up ongoing unsourced garbage from publications that should know better than to claim a wee iPad is definitely due this year. Or possibly next year. But it’s definitely due! Honest!

The short of the thinking in this case is that a 7.85-inch iPad would result in a device with the same PPI as the original iPhone, and would therefore conform to Apple’s Human Interface Guidelines:

[When] Apple was designing its first iPhone (circa 2006), company engineers determined through testing that the minimum comfortable size for an interactive element on a touchscreen display is 44 x 44 pixels. Anything smaller would yield erratic results. The pixel density used to arrive at this number, naturally, was that used in the first iPhone — again, 163 PPI. […] In layman’s terms, all this simply means [is] that no app has tappable input zones smaller than Apple’s approved dimensions. Whatever the size of a given menu option in a given iPad app, it cannot shrink beyond Apple’s pre-established minimum. It might take a bit more hand-eye coordination, but overall interaction should not be affected.

This all sounds great until you realise that one of the fundamental aspects of iPad design isn’t slavish adherence to minimums, and that all existing apps have been designed for the current form factor. In other words, app designers haven’t been thinking about what-if scenarios such as a mythical 7.85-inch iPad—they’ve been optimising their creations for the 9.7-inch screen on the current models. That goes for everything: multitouch interactions; UI components and navigation; text sizes; and so on.

Arguing everything would be fine if a 7.85-inch iPad arrived with a 163 PPI screen is nonsensical. At best, existing apps would be fiddlier to use, causing more hit errors, and the text within them would be smaller and therefore harder to read. Apple to date has rarely been about compromising user experience in order to force itself into another market segment, and so I can’t see it doing that with the iPad. Additionally, Apple’s clearly moving its entire iOS line to pin-sharp Retina displays, and so why would it release a new product with a far inferior display to existing ones? Far better to perhaps power-up the iPod touch with 3G and improved electronic guts, thereby turning that device into a more viable iPad mini.