Great point!

It's not that Fitts' Law forgot it, but that the designer of "infinite height" menu bars (Bruce "Tog" Tognazzini) didn't foresee today's gigantic and multiple screens, and was designing for the original Mac, whose screen was tiny and singular in comparison!

Linking to an archive.org cache since Tog's web site's https certificate expired.

A Quiz Designed to Give You Fitts:

https://web.archive.org/web/20210208235052/https://www.askto...

https://en.wikipedia.org/wiki/Fitts%27s_law

The Fitts' Law benefits of pie menus are significantly more profound than the Fitts' Law benefits of the "infinite height" menu bar that Tog describes in his classic article, especially on large screens. And they don't result in you moving the cursor far away from where you want to be next.

Fitts' Law says the target acquisition time (and error rate) is related to the target size (larger target = better, so pie menus make all the targets quite large, extending in all directions to all four edges of the screen; menu bars also do, but only in one direction, wasting three out of four screen edges), and the target distance (nearer target = better, so pie menus make all the targets uniformly quite nearby, exploiting all directions; menu bars don't minimize the distance, only exploit one possible direction (up), and you also have to move back too, so it's worse on a big screen).

Also, multiple displays that you can move between throws a monkey wrench into the "infinite screen edge". Which may be one reason why nobody (except for the beautiful weirdo in the thread above ;) ) ever puts a screen above or below another screen, or a menu bar on the left or right edge, even though Windows has always let you do that, but the Mac doesn't.

Pie menu:

https://en.wikipedia.org/wiki/Pie_menu

SimCity pie menus (X11/TCL/Tk):

https://www.youtube.com/watch?v=Jvi98wVUmQA

More SimCity pie menus (Flash/OpenLaszlo/Python):

https://www.youtube.com/watch?v=8snnqQSI0GE

Even more SimCity pie menus (Unity3D):

https://www.youtube.com/watch?v=sMN1LQ7qx9g

Blender pie menus:

https://www.youtube.com/watch?v=meVfv-ewhlk

Lots of other pie menus:

https://www.youtube.com/watch?v=2KfeHNIXYUc&list=PLX66BqHq0q...

There is another predictive model similar to Fitts' Law called "Steering Law" that applies to the narrow twisting "tunnel" from your current position, to the menu bar, through the menu and submenus, and back to where you need to be next, that you have to "steer" the cursor through in order to accomplish a task:

https://en.wikipedia.org/wiki/Steering_law

>The steering law in human–computer interaction and ergonomics is a predictive model of human movement that describes the time required to navigate, or steer, through a 2-dimensional tunnel. The tunnel can be thought of as a path or trajectory on a plane that has an associated thickness or width, where the width can vary along the tunnel. The goal of a steering task is to navigate from one end of the tunnel to the other as quickly as possible, without touching the boundaries of the tunnel. A real-world example that approximates this task is driving a car down a road that may have twists and turns, where the car must navigate the road as quickly as possible without touching the sides of the road. The steering law predicts both the instantaneous speed at which we may navigate the tunnel, and the total time required to navigate the entire tunnel.

>The steering law has been independently discovered and studied three times (Rashevsky, 1959; Drury, 1971; Accot and Zhai, 1997). Its most recent discovery has been within the human–computer interaction community, which has resulted in the most general mathematical formulation of the law.

Fitts' Law and Steering Law also apply to the forgiving pull-right submenu design that the original Apple Human Interface Guidelines described, which Tog invented, Apple forgot about (but finally rediscovered), and Amazon reinvented, which I was just writing about recently here:

https://news.ycombinator.com/item?id=32961306