The Macintosh interface was designed around running a single program at a time, multi-tasking was shoehorned in later on. The Windows 3.1 interface is a lot closer to the Macintosh interface than the Windows 95 interface is, so I think a lot of the Windows 3.1 feedback regarding multitasking and UI navigation applies there too. When Apple had the opportunity to redesign the UI for Mac OS X, they added the Dock, which is functionally similar to the Windows taskbar.
> In Windows 3.1, beginning users took over 9 ½ minutes, on average, to locate and open a program that was not immediately visible. Results were not much better for our Windows 95 prototype. These results were clearly unacceptable, given that our market research data (and common sense) told us that starting a program was users' number one task.
> Beginning users and some intermediates had a lot of trouble using the mouse, especially double-clicking. As a result, they often failed to find things in containers when the only way to open them was double-clicking.
> Beginning users and many intermediates relied almost exclusively on visible cues for finding commands. They relied on (and found intuitive) menu bars and tool bars, but did not use pop-up (or "context") menus, even after training.
> All but the most advanced users did not understand how to manage overlapping windows efficiently. Beginners had the most trouble-when they minimized a window, they considered it "gone" if it was obscured by another window. We heard many stories from educators (and witnessed in the lab) how users caused the computer to run out of RAM by starting multiple copies of a program instead of switching back to the first copy. Intermediate users were more proficient but still had trouble, especially with Multiple-Document-Interface (MDI) applications such as Program Manager and Microsoft Word. Market research data confirmed the problem by revealing that 40% of intermediate Windows users didn't run more than one program at a time because they had some kind of trouble with the process.
> Beginning users were bewildered by the hierarchical file system. Intermediate users could get around in the hierarchy, but often just barely, and usually saved all of their documents in the default directory for the program they were using. This problem (especially the novice case) was also observed with Macintosh users.
> In Windows 3.1, beginning users took over 9 ½ minutes, on average, to locate and open a program that was not immediately visible. Results were not much better for our Windows 95 prototype. These results were clearly unacceptable, given that our market research data (and common sense) told us that starting a program was users' number one task.
> Beginning users and some intermediates had a lot of trouble using the mouse, especially double-clicking. As a result, they often failed to find things in containers when the only way to open them was double-clicking.
> Beginning users and many intermediates relied almost exclusively on visible cues for finding commands. They relied on (and found intuitive) menu bars and tool bars, but did not use pop-up (or "context") menus, even after training.
> All but the most advanced users did not understand how to manage overlapping windows efficiently. Beginners had the most trouble-when they minimized a window, they considered it "gone" if it was obscured by another window. We heard many stories from educators (and witnessed in the lab) how users caused the computer to run out of RAM by starting multiple copies of a program instead of switching back to the first copy. Intermediate users were more proficient but still had trouble, especially with Multiple-Document-Interface (MDI) applications such as Program Manager and Microsoft Word. Market research data confirmed the problem by revealing that 40% of intermediate Windows users didn't run more than one program at a time because they had some kind of trouble with the process.
> Beginning users were bewildered by the hierarchical file system. Intermediate users could get around in the hierarchy, but often just barely, and usually saved all of their documents in the default directory for the program they were using. This problem (especially the novice case) was also observed with Macintosh users.