Introduction to Data Visualization Flashcards
Three fundamental types of memory in the
brain
Iconic memory (a.k.a. the visual sensory register)
Short-term memory (a.k.a. working memory)
Long-term memory
Iconic Memory
Similar to the graphics buffer of a computer, briefly stores what the eyes see until it is either moved into short-term memory for conscious processing or is discarded as nonessential.
Short-term memory
Like RAM in a computer: readily accessible for highspeed processing but limited in capacity
Is where the real work of sensemaking is done.
Long-term memory
Information that’s deemed worthwhile for later use is moved from short-term memory into long-term memory, where it’s stored for future retrieval, just like on a permanent storage device of a computer
Most important things about short term memory
- It is temporary
- A portion of it is dedicated to visual information
- It has a limited storage capacity
These limitations must be considered when designing data visualizations
Number of data components that encode different meanings in a graphic (for the user to be able to make sense)
No more than five
When we perceive an object, that perception is constructed from a combination of two simple visual attributes:
Shape and Color
Preattentive processing
Perception of the basic visual attributes: Shape and Color
Attentive processing
The concious part of perception
A common way to describe color combines three attributes:
- Hue
- Saturation
- Lightness or brightness
What is Hue (color characteristic)?
Hue is a more precise term for what we normally think of as color
(red, green, blue, purple, etc.)
What is Saturation (color characteristic)?
Saturation measures the degree to which a particular hue exhibits its full, pure essence
What is Lightness/Brightness (color characteristic)?
Lightness (or brightness) measures the degree to which any hue appears dark or light, ranging from fully dark (black) to fully light (white)
Attributes that intensity refers to:
Intensity refers to both saturation and lightness
Use of color: four best parctices
Choose two color palettes
Use color sparingly (not too often)
Cultural aspects
Design with colorblind in mind
Choose two color palettes: for what?
One for standard use, other for emphasis
Use of color: cultural aspects
Red does not signify that something is important, urgent, or a problem in all cultures. For example, in China, red connotes happiness!
When communicating to international audiences, it may be important to consider the connotations colors have in other cultures.
Use of color: design with colorblind in mind
Varying intensities of any single hue are distinguishable by everyone
8 Attributes of Form
- Orientation
- Line Length
- Line Width
- Size
- Shape
- Curvature
- Added Marks
- Enclosure
Line width can be useful for?
For highlighting purposes.
When lines are used to underline content or, in the form of boxes, to form borders around content, you can draw more attention to that content by increasing the thickness of the lines
How can you use relative sizes of objects in a dashboard?
Can be used to visually rank their importance.
How can you use Enclosure?
- grouping sections of data or,
- when used sparingly, highlighting content as important
Encoding quantitative vs. categorical data
Communicate quantitative data: perceive one thing as greater than others in some way (bigger, taller, more important)
Communicate categorical data: perceive that items are distinct from one another, without any sense of some being greater than or less than others.
Which two preattentive attributes can be accurately used to encode quantitative values?
- 2-D location (e.g., the location of data points in a scatter plot)
- Line length (e.g., the length of a bar in a bar graph)
Preattentive attributes in text
- Bold
- Color
- Italics (shouldn’t use - hard to read)
- Size
- Separate spatially
- Outline (enclosure)
- Underline
Visualização de Dados dos Questionários - 3 coisas que têm de estar presentes
- N da amostra (nº de respostas) - obrigatório~
- Caracterização da amostra:
Género
Idade – faixa etária
Estado civil
Etc. - Motivação:
Listar opções
Outra (texto livre) -> requer tratamento de dados para apresentação no relatório
