#20: Sketch Principles

1. Five Have

• Perceptivity of Recognition
• Recognition must be build upon human's perception, so a sliding window used in a sketch recognition is different from one used in a computer vision application.
• Intuitive UI
• According to many paper such as  KimChi paper, the role of interface is very important for efficient sketching
• High tolerance
• This can be also explained by the sliding window of a computer vision application. If the tolerance is low, the difference which users are not able to find will bring different results. Then, this can cause low usability.
• less constrains
• Users want to draw sketches with computer in the way they draw with a pen and a paper. Constrains hinder free sketches.
• Consistency
• Same input - same output

2. Five Have not

• Inconsistency
• Same input - different output
• Many limitations
• Not allow users to sketch drawing in their own way
• Poor editing
• Editing takes a major portion of sketching. If it is poor, there is not much benefit.
• Bad UI
• Lower usability
• Low tolerance
• Users want to draw a horizontal line, but the line might be a little curved or leaned. if tolerance is low, this line or most lines drawn by users cannot be interpreted as a horizontal line.