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/Datamaps.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 = ?