Usability Case Study: Datamaps Visualization

1
Usability Case Study Datamaps Visualization

• Chris North
• CS 3724 HCI

2
DataMaps

• DataMaps http//infovis.cs.vt.edu/census/Datamap
  s.htm
• Color map
• Select for detail table
• Histo Sliders filter
• Plot brushing
• Sticky note help

3
Usability Videos

• Succeeded at easy task
• Sticky Help sometimes useful, terminology tricky
• Problems
• Map navigation, want to go back
• Click instead of drag sliders
• Think histogram is barchart, each bar is a state?
• Never colored map
• Never used plot
• How to find other data fields (More Variables)
• Filtering mis-interpreted
• Stuck in table, not using visualization

4
Re-design Ideas

• Users familiar with data table concept
• Variables (population,)
• States
• Table-first approach
• All variables accessible via treeview (Win
  Explr)
• Data shown for selected states
• Entice users to visualization
• Pop-up when click variable
• drop here

5
Wizard of Oz

• New table design successful
• drop here failed (drop what here?)
• Should group map and histo for an attribute
• Wiz-of-Oz hard with dynamic visualization!

6
Histo Slider Re-design

• Designs
• Smooth curve (black), instead of bars
• Selection range (yellow), selection curve (red)
• Brushing (direct selection in histo) vs sliders
• Slider thumb variations
• On, above, below
• Squares, triangles
• Between thumbs bar, button, circle
• Text input boxes, range
• Results
• Smooth curve successful, understood humps
• Brushing used, sliders not used
• Brushing clicked first, but eventually drag
• Text boxes good, but can override vis.

7
Clean Design

• Rob Miller, MIT visually integrated design
• Brad Paley, Didi / Columbia eliminate typical
  windows paraphernalia

8
Other

• Moving users from table to visualization
• Progressive usage
• Post-it help
• Histogram design, interaction
• Brushing instead of filtering, single
  interaction model

9
Fun Verbal-visual conflict
10
Fun How to Lie with Visualization
11
The hidden 0-points

• Lie factor ?