Abstraction Visual Abstraction: Velázquez, Picasso and Klee What makes abstract art challenging, and what makes it good?
Abstraction Writing Systems: Signs, Icons, Symbols and Abstraction How does abstraction help to make writing a tractable problems for the human brain?
Abstraction Layers of Abstraction The essence of abstractions is preserving information that is relevant in a given context, and forgetting information that is irrelevant in that context. – John V. Guttag