Encodes association between items using spatial proximity
Order of splits has major implications for what patterns are visible
No strict dividing line
View: big/detailed
Contiguous region in which visually encoded data is shown on the display
Glyph: small/iconic
Object with internal structure that arises from multiple marks
Partitioning: List Alignment
Single bar chart with grouped bars
Split by state into regions
Complex glyph within each region showing all ages
Compare: easy within state, hard across ages
Small-multiple bar charts
Split by age into regions
One chart per region
Compare: easy within age, harder across states
Partitioning: Recursive Subdivision, Part I
System: HIVE
Split by neighborhood
Then by type
Then time
Years as rows
Months as columns
Color by price
Neighborhood patterns
Where it’s expensive
Where you pay much more for detached type
[Configuring Hierarchical Layouts to Address Research Questions. Slingsby, Dykes, and Wood. IEEE Transactions on Visualization and Computer Graphics (Proc. InfoVis 2009) 15:6 (2009), 977–984.]
Partitioning: Recursive Subdivision, Part II
System: HIVE
Switch order of splits
Type then neighborhood
Switch color
By price variation
Type patterns
Within specific type, which neighborhoods inconsistent
[Configuring Hierarchical Layouts to Address Research Questions. Slingsby, Dykes, and Wood. IEEE Transactions on Visualization and Computer Graphics (Proc. InfoVis 2009) 15:6 (2009), 977–984.]
Partitioning: Recursive Subdivision, Part III
System: HIVE
Different encoding for second-level regions
Choropleth maps
[Configuring Hierarchical Layouts to Address Research Questions. Slingsby, Dykes, and Wood. IEEE Transactions on Visualization and Computer Graphics (Proc. InfoVis 2009) 15:6 (2009), 977–984.]
Partitioning: Recursive Subdivision, Part IV
System: HIVE
Size regions by sale counts
Not uniformly
Result: treemap
figcaption.reference [Configuring Hierarchical Layouts to Address Research Questions. Slingsby, Dykes, and Wood. IEEE Transactions on Visualization and Computer Graphics (Proc. InfoVis 2009) 15:6 (2009), 977–984.]
Partitioning: SpaceTree
System: SpaceTree
Partition subtrees as thumbnails
Superimpose
Superimpose Layers
Layer: set of objects spread out over region
Each set is a visually distinguishable group
Extent: whole view
Design choices
How many layers, how to distinguish?
Encode with different, nonoverlapping channels
Two layers achieveable, three with careful design
Small static set, or dynamic from many possible?
Static Visual Layering
Foreground layer: roads
Hue, size distinguishing main from minor
High luminance contrast from background
Background layer: regions
Desaturated colors for water, parks, land areas
User can selectively focus attention
“Get it right in black and white”
Check luminance contrast with greyscale view
[Get it right in black and white. Stone. 2010. http://www.stonesc.com/wordpress/2010/03/get-it-right-in-black-and-white]
Suprimposing Limits
Few layers, but many lines
Up to a few dozen
But not hundreds
Superimpose vs. juxtapose: empirical study
Superimposed for local, multiple for global
Tasks
Local: maximum, global: slope, discrimination
Same screen space for all multiples vs single superimposed
Dynamic Visual Layering
Interactive based on selection
One-hop neighbour highlighting demos: click vs. hover (lightweight)