Chapter 4: Phy-dig-world

Phy-world is short for physical-world, which means the traditional world without IT-technology, such as book and pen. 

Dig-world is short for digital-world, which means the IT-world.Mix-world means the mix of physical and digital world

The design of software is informed by the design of physical world:

      ---Amazon’s tab is created by getting an inspiration: a file folder.

Then physical world learns from the digital world:

      ---Many books, especially children books are designed with the characteristics of interactive functions which are typical in digital world.

The caution on the lack of sensing and touching in the digital world.