This concept is absolutely invaluable to the practice of interface design. For our purposes, the definition omits a key connection: How do we know what those properties offer to us?

• 这个概念毫无疑问对于界面设计工作有着巨大的价值，但是对于我们的设计工作来说，它忽略了一个关键联系，即如何知道提供给我们的特性是什么?