I read these before, so I just took some quick notes:
Djajadiningrat, Gaver, and Frens
Usability often means ease of use rather than exploration, which can be mundane. Aesthetics of interaction shifts to a more enjoyable experience. Two methods of discovery: interaction relabeling with a non-electronic mechanical device (I will bring in a wine key for this exercise) and extreme users not prototypical, like a drug dealer or the pope.
Norman1
Easy things should be easy to understand. If it requires a sign, it’s poorly designed. Switches should have some relationship to the real world so that there is visibility and understanding of function. Also feedback from the object that you are doing the right thing is helpful. My example of this would be the keyboard on a touchscreen like the iPad. There is no tactile response that you have touched the keys like on a traditional keyboard.
Norman2
Unlike an interactive work space or constructivist learning, books and instruction sets are seen as inferior because they do not offer any method of feedback and interaction, unless a user pauses for reflection. It’s not inherent. A set of symbols changes the represented world into the representing world.