Some line had to be drawn at which features were used most often; those that their user data said were used less frequently were the ones that were moved to other tabs (i.e, not the "Home" tab).

BTW, the "auto-fit" option is on the "Home" tab in Excel 2007; it's in the "Cells" group, under the "Format" button.

There is no "algorithm" in the ribbon, unlike in earlier (menu driven!) versions of Office.

Unlike the menus in, say, Office XP or Office 2003, where some items were "hidden" until you used them, in the ribbon EVERYTHING is there. It doesn't try to "adapt" to you. Sure, you have to re-learn where a lot of stuff is, but that was often the case before the ribbon came out as well (because more features kept getting squeezed into a menu-driven UI that just wasn't made for a program with that many options).

The only thing that changes in the ribbon are some contextual tabs that show up at the end, e.g., when you have selected a picture or a table. These tabs are meaningless normally, so they are hidden. But they don't re-arrange themselves based on your usage patterns - they are static and don't change.

Well.. yes, and no. Bob and Clippy were certainly the result of research I'm sure, but not the kind of research that went into the ribbon.

The ribbon was built using feedback from that program in Office which started in... Office XP I think ... that let you send usage data back to Microsoft. So unlike all previous versions of office, with the ribbon Microsoft actual had REAL data to go on, from a much larger sample than they ever could have put together in their UI testing labs. And that can make a really, really big difference!

The link you are probably looking for is this one:

http://blogs.msdn.com/jensenh/archive/2006/11/10/the-office-2007-ui-bible.aspx

It's a link to Jensen Harris's Office 2007 blog, where he collects all the articles he wrote about the Office 2007 UI (the "ribbon"), explains WHY it is the way it is, provides (IMHO) rather insightful comparisons against the old menu & toolbar paradigm, and generally does a good job of explaining why they chose the ribbon over the "status quo" of toolbars and menus.

That said, a ribbon-based UI is not always the answer - like toolbars and menus, it can be abused by people who don't think UI design through carefully enough, but it is a clever and intuitive answer to "option overload."

No, that's what we call an ANALOGY, or for the nitpicky among us, a SIMILE. Even though the poster did say "exactly like," its clear from context that they were not speaking literally. No need to get so worked up about it. (Unless, y'know, you enjoy getting worked up like that.)

Nicely done. :-)