I have just read Raymond’s User interface design for interior door locks which reminded me of a curiousity.

 

Take a look at your telephone’s numeric keypad. The top row of buttons on mine is 1,2,3. Now look at your computer keyboard numeric keypad or a calculator keypad. For mine, the top row is 7,8,9.

 

A mnemonic to remember a phone number is to visualize the physical path traveled as your finger pushes consecutive digits. It’s inverted when dialing from the keyboard.

 

Go figure

 

 

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