assingment on humam computer interaction

Chapter 5 Questions 

1. Define direct manipulation Describe the benefit and potential problems.

2- What are the three principle of direct manipulation?

3- What are the guidelines for effective use of icons?

4- What are the guidelines for adding 3-D elements to an interface without undermining usability?

Chapter 7 Questions

1- describe the characteristics of a well-structured command language.

2- What are the guideline for creating usable abbreviation for command set?

3- Explain the benefits and limitations of Natural Language Interaction (NLI)