I see design principles—software design—all around me. They must be following me. The last time was at the library, the brick-and-mortar place with dusty tomes lined up in rows and columns. I was searching for a map of Ernest Shackleton's* ill-fated Antarctic trip.

I found in my library's computer three in-stock books. One I located on the shelves; two I couldn't find. I got a librarian; she wrote the Dewey decimal numbers; she looked; she couldn't find 'em either. Defeated, she noticed the numbers included a pre-fixed "J," and sent me at last to the "Junior" section.

In the junior section I found only book #2; I asked the junior librarian for help; she couldn't find book #3; I eventually noticed book #3 on prominent display above the shelves... promoting itself to browsers yet hidden to those using the Dewey decimal mode ("card catalog system" for you old folks).

The problem is equivalent to one of "modes." In his book entitled Humane Interface, Jeff Raskin rightly complained that modes of operation are usually problematic. They hide whole aspects of functionality, confuse the user as to which mode is active, and wreak havoc when you are unintentionally in the wrong mode. The solution in the library is to use a single numbering sequence that encompasses even junior books. Never mind that I didn't spot that "J"—I'm blind to that sort of stuff 'cause I'm rigidly structured... the librarian didn't even spot it until she was frustrated. Modes cause blindness of unfamiliarity and disbelief because systems make us machines, usually for the better... until the modes break our sense of structure. Then books can't be found, computers don't work, and planes even crash.

So I walked out of the library amazed that I had to contend with three retrieval modes: adult, junior, and display. A final note to the story, I had actually started my quest seeking a fourth book, one I had previously borrowed from the very same brick building. Alas, it was not even listed as a resource at that location (on hand or not)... yet it showed up at others. My point is that the library could have listed it as discarded. I looked in the giveaway box at the front door and there was the book I wanted... stored in mode #4!

*Shackleton's shipwreck is by my reckoning "Man's Greatest Story of Survival and Rescue." They lived for 16 months on icebergs, traveled 800 miles in a dingy across the Cape Horn Rollers (the only seas on the globe where the lines of longitude are uninterrupted by land mass), traversed an uncharted 6000 ft. glacier mountain with a 50 ft. rope and a Sterno can, and made four subsequent voyages to rescue their crew left behind. Tell me a better one.