Comment by JonathonW

There was a lot of real-world usability research that went into the Office 2007 ribbon-- both qualitative and quantitative. Jensen Harris went into some of this in his blog; see, for example, https://docs.microsoft.com/en-us/archive/blogs/jensenh/more-... .

More here: https://docs.microsoft.com/en-us/archive/blogs/jensenh/table...