This is the fourth article in a series on common usability and graphical user interface related terms [part I | part II | part III]. On the internet, and especially in forum discussions like we all have here on OSNews, it is almost certain that in any given discussion, someone will most likely bring up usability and GUI related terms - things like spatial memory, widgets, consistency, Fitts' Law, and more. The aim of this series is to explain these terms, learn something about their origins, and finally rate their importance in the field of usability and (graphical) user interface design. In part IV today, we focus on 
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Member since:2006-05-26
You make excellent points, but other than it not becoming less important with training, there are a lot of people out there with less than ideal coordination due to whatever reasons, and Fitt's Law is their friend: with certain limitations people may have, no amount of training will make it easy to hit something, because they just don't have the coordination for it.
Also, even with training, IIRC Apple (or someone else) showed that because there's a high probability that the user will overshoot their intended target, they automatically slow down their mouse movements, to the point where the time taken to move the shorter distance (compared to the global menu on the side of the screen) actually increases: thus, it still matters for actual speed: the only thing that changes is user's perception of whether it's faster to have a localized menubar or a global menubar.
Admittedly, once you have more than one application in use, it can be rather confusing as to which one holds control of the menu bar, and the menu changing quickly can quite possibly be disorienting: in that respect, having the menubar attached firmly to the window it controls is less confusing.
Member since:2006-02-05
Pretty sure you read that from Bruce Tognazzini's askTog site, I know thats where I did ;-)
On top of that, according to Jeff Raskin's "The Humane Interface", the brain uses a measurable amount of energy when using a user interface (something we can't accurately or safely measure yet, but still). He says that the amount of brain power required to operate any given interface is an indication of how well it is designed, something that forces the mind to work in ways it doesn't handle well will take more energy, and something designed with cognative psychology in mind will take less.
Member since:2005-09-21
It's funny when people advocate a global menu bar based on Fitts law. Sure, with equal distances, and a knowledgeable user, and given the task is to access a menu, a menu bar on the edge of the screen is faster than one not on the edge. However there are a lot of confounding factors.
1. A local menu bar if often much closer to the mouse. For example, an IM window on the far right of the screen has a local menu bar very close to the application content, rather than across the screen. Also if you have two screens, you might have to move all the way across two screens to get to your menu. Hard to compare which is faster then.
2. Accessing a menu in an inactive app requires two actions with a global menu bar, activate and click.
3. The user must know they can click on the edge of the screen. I don't think I've ever seen a non-technical user take advantage of screen corners. New users precisely aim at these buttons just like any other button.
4. The assumption is that the menu is an important UI element to access. This is not true for myself, since I barely ever use the menu in any application. Putting the menu at the top steals that space from other widgets that could potentially go there (for me this is the minimize and close buttons of a mazimized application).
Usability is never as simple as a formula.
Member since:
2006-02-05
First off, great article (as usual) Thom.
I can confirm, Vista's start "orb" can be activated by the corner. One that you missed is you can close a maximized window by the upper right hand corner as well. Which is kind of funny, because in Vista, that means that the button "Hit area" extends a good 15 pixels beyond the visual indication, and only when the window is maximized. Same thing with the start orb, visually one would think that it wouldn't work, but as soon as you try, you get the right (if inconsistent) behavior.
As for Fitts' law becoming less important with training, I disagree. A badly done interface element will always be harder to use then a well done interface element. Just because the guys in the worlds strongest man competition CAN throw logs like they are sticks does not make throwing logs easy, even though their training has brought them to the point where they can do it as easily as normal guys could through a stick. Same deal with interfaces, just because you are an expert at using a poorly defined interface doesn't make the design irrelevant, and if you compare to a guy who has the same amount of training on a well designed interface, at the end of the day the guy on the well designed one will have more energy doing the same thing. Case in point, I have been using computer mice for about twenty years now, and I still find it easier to hit corners then 40x10px menus floating in the middle of the screen.
HOWEVER, I completely agree with you that Fitts' Law is blown completely out of proportion by armchair designers. You would think by talking to some people that it is the one and only concept or heuristic in interface design, and the sole metric one uses to judge the worth of an interface.