In your opinion, what does it mean to design for people/end users (“Human Centered Design”)?  Provide an example of how something is designed using this approach. Donald Norman describes various psychological concepts or principles of good design including: Affordances, Constraints, Mapping, Feedback and Conceptual Models.  Select 3 of the concepts. Describe each one, and provide an example of each. Provide one example of a “Norman Door” or other object you have encountered that should be simple, but is difficult and frustrating to use.  Why is it difficult/frustrating?  Considering non-technical issues (e.g., human factors, social, economic, cultural, political, environmental, ethical) why, in your opinion, was the object designed that way?