Fitts' Law and Infinite Width

Interesting read, including the comments. What a variety of working habits people have!

In the long run, habit matters more than theoretical calculations about which set of habits would be best. See the QWERTY keyboard, which is not the most efficient layout, for English or any other language. But we keep it - because we’ve gotten used to it. Changing our habits for 10-15% increase in speed is pointless at this stage.

IOW, some standard GUI layout and features should be found on any and every OS, and on any and every application. I don’t much care what it is, as long as I don’t have to relearn mouse and hand gestures every time I use another OS or application.

Well, I do care about one thing: clicking on any object should bring up a context-sensitive menu. And I do like sub-task menus (such a for printing) to open up in nice little panes of their own, which I can move around to where I want them. But I won’t insist on that.

For those who want to be different, optional features could be available, either system-wide or for a given application. We have enough hardware to store all this extra stuff, so why not do it. I’m sure there are lots of unemployed computer science students around who would be only too happy to work on the coding. :wink:

Cheers,

Wolf Kirchmeir
Blind River, Ontario

You’ll be glad to know that the Start button in Windows 7 is infinitely tall.

The reason Fitts’ Law is ignored is that other aspects of GUI design are more important. I use both a Mac Powerbook and a Windows XP box, and much prefer the Windows design.

wolf k.

Hi, wat is everyone chattin bout??

I know this is already a three-year-old post and no one is likely to agree with me on this, but the correct spelling isn’t “Fitts’ Law”, it’s “Fitts’s Law”. It would be “Fitts’ Law” if, say, two brothers with the last name Fitt came up with it. But it is named after only one scientist, named Fitts.

I feel your touchpad pain - that is (IMO) (one of) the best features of my iBook/OS X combo - using two fingers to scroll rather than the touchpad edges. The number of times I’ve tried to scroll with two fingers on a PC since I got the iBook…

I’m with Paul on that. I see how a consolidated menu system would be simpler for novice users; it’s the same reason Windows added the Start menu. Keep things simple, consistent, and in one place to make it harder to get lost or confused.

After some computing experience, a user learns to multi-task, and the Mac menus can be really frustrating. It’s a paradigm shift - like when a child learns that objects which are out of sight still exist. At that time, it no longer makes sense for “the computer” to own the menu, since conceptually they’re no longer in a generic “working on the computer” state, they’re editing a paper / buying music / sending an e-mail / state. From that point of view, Fitt’s law says two different things - from a physical mouse movement point of view, it makes sense to consolidate menus at the top to give them that infinite height. However, from a logical point of view, we’ve created unnecessary distance between the work area and the control area, so the mental movement is greater.

In the case where we’re only working on one thing, we maximixe the application and we’ve got something pretty close to the Mac interface (although I agree that we don’t get that infinite height thing). We’ve also got the option to multi-task, which is enhanced by being able to see several menu bars at one time.

I’ve been enjoying using a Wacom tablet as my primary pointing device, largely because it’s an absolute pointing device. The start menu is at a fixed point on the tablet, and after a few days of use I can just about click it with my eyes shut. I’m still hoping for ubiquitous touch-screen or pen enabled monitors some day.

@ Jeff

“I think Windows does a good job utilizing the edge at bottom of the screen with the taskbar (which, by the way, unlike Apple’s one-screen menus, can spread across multiple monitors in a logical way) and start menu. I just wish we had more stuff along the top edge!”

Fitts’ pornography or not, “Start Menu” = Fail and Windows still fails miserably in regards to usability overall.

  1. Because the main menu is on the bottom
    People naturally read from top to bottom, left to right (unless you’re reading Hebrew or Arabic). Try dragging the taskbar to the top of the screen. After adjusting to it, everything will feel easier and more natural.

  2. You always have to mouseover (and wait for the delay) on a link (all programs) just to see the second level of the menu (which is what you really wanted to see 95% of the time anyway). I work REALLY fast when I get into the zone. Every time I hit that 500ms-1sec wall I scream subconsciously.

  3. There’s no logical categorization of applications. The start menu is at the complete mercy of the individual application developers. Which means that they can(and will) place folders with their companies name, followed by a sub menu with their application. Or, multiple sub menus with irrelevant/useless tools or links to market their website. <sarcasm>Let me tell you, I love whoring out my OS to application marketing</sarcasm> <sigh /&gt.

  4. What is an operating system’s sole purpose. Serving files and applications right. Then, doesn’t it make sense for links to files (My Computer/My Documents) and applications (Start->All Programs) to, not only have the same weight (size, dimensions, relative location), but also to be sufficiently large enough to make it easiest to click them with the mouse?

That’s why docks kick a**. Note: not to be confused with docking
<NSFW>http://www.urbandictionary.com/define.php?term=docking </NSFW> (sorry, couldn’t resist >:P). Not only does it live on the edge of the screen (usually bottom or left depending on user preference). Icons you mouseover grow in size raising their weight(relevance) in importance(the app you want to use) and making it absolutely obvious which application you’re going to open.

I could go on for hours about the shortcomings of the Window’s UI (the “My” prefix <sigh />, etc…) because I’ve spent countless hours hacking it into something more friendly to my workflows. Don’t get me wrong, I love working in windows. I just hate the shell’s UI.

To avoid making this post any longer. Here’s a screenshot of my current *nix layout to illustrate.
http://dl.dropbox.com/u/425505/Screenshot-1.png

I’ve heard this argument before, but unfortunately, it’s not true. I’m not saying that empirically, Mac users aren’t faster at using the menubar than Windows users-- I don’t know, I haven’t tested them. But the large differences you speak of would not be accounted for by Fitts’ Law.

See, Fitts’ Law is inherently designed to account for movement in 1-dimension. That doesn’t stop people from applying this law to movement in 2 dimensions, even though the law only allows for one “width” parameter.

How can they do that? Well, there are a variety of ways, several of which are outlined in MacKenzie & Buxton’s influential paper “Extending Fitts’ Law…” What they found, comparing several different methods, is that the law is most accurate when using the smaller of the two sides of a rectangle as the width parameter in Fitts law. Thus, while one dimension of the target (menubar) is effectively infinite in width, the other is actually quite small.

While there may be differences in pointing time by making the larger side ever larger, these differences are not accounted for in formulations of Fitts’ Law, and in general the RT differences are not nearly as dramatic as those described here.