Paper size and user interface design
In a prior post I tried to make clear why today's common idioms in user interface design are horribly inefficient on today's screen sizes. Thinking about this a bit later, I realized there is something I did not mention - the single common basis for why the old trade-offs once made sense, are now complete non-sense, and has to do with the size of a piece of paper.
Most of the information we present through software (content, not decorations) is organized to present well on an ordinary letter-sized piece of paper. Once the width of a screen became wider than letter-sized paper, we no longer needed to be severely constrained in our use of horizontal space. We crossed a threshold. Now even the lowest-end screens (at 1280x800) are much wider than paper.
Why should an ancient medium like paper have anything to do with modern user interface design? Common paper sizes are - in effect - the result of a centuries-long experiment in user interface design. Paper can easily be fabricated in practically any size and shape. The paper sizes we use are the result of human choice, not a limitation somehow imposed by the manufacturing process. The range of paper sizes we most commonly use today are the result of generations of humans choosing what works best.
If you compare screen size to paper size, the old trade-offs make a lot more sense. There was for a long time - as long as 800x600 (or smaller) screens were significant - a very strong motivation to place overhead elements on the top and bottom of the screen, and not on the sides. For those small screens the cases where content was wider than the screen were not rare. For anything text-like, usage that requires horizontal scrolling is horribly inefficient (for the human, not for the computer). Any design element that took away from horizontal space for content was going to force an ever larger fraction of usage into horizontal scrolling. Put simply, screens were effectively narrower than paper and best design required preserving as much horizontal space as possible for content.
The old trade-offs did in the past make a lot of sense.
A low-end 1280x800 14-inch laptop screen is about 11.9 inches wide and 7.4 inches tall. Given the content area on letter-sized is about 7.5 inches wide and 10 inches tall, the screen about 2.6 inches too short and 4.4 inches too wide. Hold a piece of paper up against the screen, and the problem is pretty clear.
Have to admit: when "widescreen" panels first started to appear on laptops, I was hoping this was an aberration, not a trend. Unless you spend all your time watching movies and playing video games, most of the content you look at is text-like, and "widescreen" is not efficient for this sort of content. By now it seems very clear that we are going to be stuck with this form-factor for a very long time, and must adjust our design-habits to match.
There is a good deep/underlying basis that justified the old design idioms on old screens. That same basis on today's "widescreen" panels makes those old idioms horribly wrong.