Craig Mod has written a lengthy and well-informed piece on A List Apart about the problems of designing for the iPad and other “browser”-based interfaces. He makes some particularly important points about the differences between products which have a spine as the “axis of symmetry” (e.g. books, magazines), and digital products where the axis is hard to place:

“If the axis of symmetry for a book is the spine, where is it on an iPad? On one hand, designers can approach tablets as if they were a single sheet of “paper,” letting the physicality of the object define the central axis of symmetry—straight down the middle.

“On the other hand, the physicality of these devices doesn’t represent the full potential of content space. The screen becomes a small portal to an infinite content plane, or “infinite canvas,” as so well illustrated by Scott McCloud.”

The core of his article is a design template for long form tablet reading, for which Mod breaks tablet reading distances into three main categories: Bed, Knee, and Breakfast

• “Bed (Close to face): Reading a novel on your stomach, lying in bed with the iPad propped up on a pillow.
• “Knee (Medium distance from face): Sitting on the couch or perhaps the Eurostar on your way to Paris, the iPad on your knee, catching up on Instapaper.
• “Breakfast (Far from face): The iPad, propped up by the Apple case at a comfortable angle, behind your breakfast coffee and bagel, allowing for handsfree news reading as you wipe cream cheese from the corner of your mouth.”

An image of the template in action is shown above. It’s released under the MIT licence.

Although the article is written with ebooks in mind, the principles can obviously also be applied to magazine and news apps. Worth a read.