The Office User Interface Blog has a post (kind of old now) about the most commonly used features in Microsoft Word 2003.
Top 5 Most-Used Commands in Microsoft Word 2003
- Paste
- Save
- Copy
- Undo
- Bold
Together, these five commands account for around 32% of the total command use in Word 2003. Paste itself accounts for more than 11% of all commands used, and has more than twice as much usage as the #2 entry on the list, Save.
Paste is also far-and-away the number one command in Excel and PowerPoint, accounting for 15% and 12% of total command use, respectively.
Beyond the top 10 commands or so, however, the curve flattens out considerably. The percentage difference in usage between the #100 command ("Accept Change") and the #400 command ("Reset Picture") is about the same in difference between #1 and #11 ("Change Font Size") This is what makes creating the new UI challenging–people really do use a lot of the breadth of Office and beyond the top 10 commands there are a lot of different ways of using the product.
That last part really brings home the idea that people only use a fraction of the functionality in Microsoft Office but it’s a different set for each person.
(Hat tip to Jeff Atwood for the link.)