Radar Charts!

Sheena Ellenburg

Outline

• Overview– Characteristics– Nomenclature

• Usage• Examples

Overview - Characteristics

• 2-D• 3 or more quantitative variables represented

as axes starting from the same origin– Equi-angular spokes called radii– Lines drawn between points to form a polygon

• Relative position and angle of the axes generally not informative

Overview - Nomenclature

• Also known as:– Web chart, cobweb chart (gridlines)– Spider chart (gridlines)– Star plot (no gridlines)– Irregular polygon– Polar chart (angular significance)– Kiviat chart (acceptable range bands)– Stardinates (Lanzenberger, 2003)

Usage

• Ideal Data:– Multivariate (mas que 3)– Many Quantitative to One Nominal• Sports players attributes, companies, coffee beans

• Questions:– Which records/observations are most similar

(clustering)– Which records/observations are dissimilar• Are there outliers?

When to Use a Radar Chart

• If you can’t accommodate different quantitative scales in a bar graph

• If the objective if to compare symmetry rather than magnitudes– Stephen Few’s resort example

• Data fits circular display intuitively (counter/clockwise reading order is either explicitly obvious, or is unimportant)– Clocked data– Coffee bean taste attributes

Examples

Spider/Web/Cobweb Chart

Star Plot

Polar Chart

Kiviat Chart

“Stardinates”

[Lanzenberger, 2003]: Lanzenberger, M., "The Stardinates - Visualizing Highly Structured Data", Proceedings of the Seventh International Conference on

Information Visualization (IV'03), 2003.

Cupping Scores

• SCAA Cupping Protocols

• Sweet Marias Coffee Achives

How to Taste an Oyster

• Tomato - The insider's guide to food and drink in Melbourne

European Sensory Network: Sensory Profiles of three German beers

http://www.esn-network.com/635.html

More examples of food research

• http://www.cjbio.net/html/innovation/food_application.asp• http://www.sciencedirect.com/science/article/pii/S09503293

09000226

References

• Kiviat Diagram: www2.cs.uidaho.edu• Polar Chart: advsofteng.com• Spider chart, star plot: wikipedia.org• Stardinates: infovis-wiki.net• Verghisgroup.com – 3 Things to Think About – A

Warning Label for Radar Charts• Few, Stephen. Keep Radar Charts Below the Radar

– Far Below. 2005. Perceptual Edge.