Regardless of the original claims on keyboard versus mouse (there is more recent work on that subject), there are some really nice gems in the article and comments, that are still relevant for current interfaces:

" Guideline: The keyboard interface must not dictate the design of the visual interface.

Guideline: The work to design and build the keyboard interface should not sap resources that are needed for the creation of the visual interface. "

Nolan Larsen from WordPerfect Corp. puts it nicely:

" ... When scrolling the text horizontally in a window we would refresh the text by redisplaying each line starting at the top. This resulted in a wave of text rippling down the screen, and many complaints that the screen refresh was too slow. The remedy was to scroll the bits already on screen and then redisplay each line from the top. The second implementation was actually slower than the first because we incurred the overhead of scrolling the bits before we even started to display the new text on the screen. However, the perception was that there was an immense increase in speed. We stuck with the second implementation because it increased the overall satisfaction of the user even though it actually decreased the throughput of the product.

In my mind, perception is stronger than reality. A user’s perception of a product is what causes him to purchase it and influences his satisfaction with the product... "