Mark and Channels Flashcards
What are marks?
Geometric primitives that represent items or links
What are channels?
Control appearance of marks based on attribute
What are some example of marks?
- Points
- Lines
- Areas
- Connections
What are some examples of channels?
- Position
- Colour
- Shape
- Tilt
- Size
What is redundant encoding?
Using multiple channels to send stronger message
What do we mean by expressiveness?
Visual representation should represent all and only the relationships that exist in the data
What is effectiveness?
How well does a channel highlight a piece of information
What are the the most to least effective channels for ordered attributes?
Most
- Position on common scale
- Position on unaligned scale
- Length
- Tilt
- Area
- Depth
- Colour
- Curve
- Volume
Least
What are the most to least effective channels for categorical attributes?
Most
- Spatial region
- Colour hue
- Motion
- Shape
Least
What is accuracy when discussing marks and channels?
How precisely can we tell the difference between encoded items.
What factors affect reading accuracy?
- Distance between marks
- Alignment
- Distractors
- Scale and their alignment
What is disriminability?
How many unique steps can we perceive?
What is separability?
Is our ability to use this channel affected by another one
What is popout?
Can things jump out using this channel?
