A bit off topic, but a couple of years ago, in my first year of computer science at University (I dropped it in favour of maths), I learned some basic ideas that designers think about when developing a GUI. I thought it was pretty interesting stuff, so I'll share some of it here:
(I'm on a Windows computer just now so it's a bit hard to reference this to Mac OS X, but I'll try):
When using fonts in a GUI, you'll notice they're all sans serif fonts (i.e. Arial). Serif fonts (i.e. Times New Roman) are avoided. Sans serif fonts are easy for us to read, and stand out visibly.
Serif fonts are best used for blocks of text (i.e. essays, novels) because the serifs at the end of strokes apparently help your eyes flow with the text, making it easier to read.
If you look at most companies logos, NO SMOKING signs, or any kind of sign you see on the street, they are all using sans serif fonts. Where as your favourite book will definietely use a serif font.
I'm using Internet Explorer just now, and at the top, I have: File, Edit, View, Favourites, Tools and Help. I was told designers should ideally place between 5 and 9 menus at the top (7 +/- 2). This is the optimum amount of things a Human can remember. If you place, say 13 menus at the top, it greatly over complicates the GUI. Try it out. I just opened Microsoft Word and it has 9 menu items: File, Edit, View, Insert, Format, Tools, Table, Window and Help.
When you click on one of those menus, i.e. File, another menu will appear. On this new menu there is a lot of reasons why things are ordered the way they are.
Notice if you click on File, then go to Open. Notice 'Open' is followed by ellipses (Open
...). These "..." implies that when you select this command, there is more feedback from the user required. For example, if you go to File and Exit or File and Quit, you'll notice there are no "..." because when you quit, the command is final, no more input is required. "Save as..." will always have ellipses as when you select the command, the OS requires more information from you to save the file.
You'll notice as well (on Windows and OS X) that when you click on a menu it has been designed so the most commonly used commands are at the top, or in some cases the more severe command is at the bottom. That is why "Quit" or "Exit" is always at the bottom of the File menu, because it is the most severe command you can use in the program, as it will close it down.
And finally, if you click on a menu, such as File, you'll notice a process called "chunking" is used. Commands which are related to each other are grouped together and separated from other commands by a horizontal line. For example, on the Edit menu of Internet Explorer:
Cut
Copy
Paste
--------------- <------ line separating cut, copy and paste.
Select All
---------------
Find on this Page...
Again, notice the ellipses on "Find on this Page" implying that when you select that command, more information is required from you. The line separates cut, copy and paste from 'select all' as these are different types of commands.
None of this has anything to do with this topic, but I never knew any of this stuff until it was pointed out to me and I think it's amazing to think that pretty much everything in the OS is designed in a certain way for a particular reason. There are probably loads of other reasons why certain things are designed in certain ways in the OS, but these are the ones covered in the course I studied.
I hope some of you find it interesting.
