#6: Sketch principles

1. A list of ten principles of things a sketch system should do 1) Intuitive error messages: what is wrong and why? 2) Intuitive function buttons: easy to use 3) Rapid feedback: time to show error messages or correct message 4) High performance of sketch recognizer: easy to draw due to well-recognition 5) Well-organized UI 6) Implement and provide only necessary function 7) Consistency: same input - same output 9) Save a user's previous sketch history well 10) Easy to edit drawing (e.g. click the drawing for naming or remove parts of it)
2. A list of ten principles of what they shouldn’t do 1) Vague error messages 2) Button of functions are not intuitive 3) Slow feedback: high occurrences of server errors 4) Bad sketch recognizer: hard to make it understand what a user intends to draw 5) Ineffective UI 6) Unnecessary functions: distracts users 7) Duplicated functions: distracts users 9) Inconsistency 10) Hard to edit drawing
3. List 5 improvements for Mechanix 1) Performance of server (too many errors pop up.)

   - Server is busy. Please try again later.

   - Read timed out 

   
   2) Checklist bugs
   
   3) Vague check messages
   
   4) Labeling failure (quite often, especially #6)
   
   5) Error #7
   
   
4. I finished the tutorial except #12.