DataTerminology.comNEW
Also known as: Spider Chart
A chart for multivariate data with axes sharing a common origin arranged radially.
DESCRIPTION
A radar chart displays multiple variables for a single or several observations on axes radiating from a center. Values are often normalized to comparable scales. It highlights relative strengths and weaknesses but can become cluttered with many series or variables. Use consistent ordering and limited variables for clarity. Alternatives like parallel coordinates or small multiples improve readability for larger datasets.
ALTERNATIVE DEFINITIONS
Wikipedia
A radar chart is a way of displaying multivariate data in the form of a two-dimensional chart of three or more quantitative variables represented on axes starting from the same point.
Canonical definition emphasizing multivariate radial axes.
Microsoft Support
A radar chart compares the aggregate values of several data series.
Focuses on comparison of multiple series for the same variables.
Data to Viz
Radar charts display multivariate data on several axes starting from the same point, but are often hard to read and compare accurately.
Warns about interpretability issues and suggests alternatives.
RELATED TERMS
Star Plot Polar Chart Feature Scaling Z-score Kiviat Diagram Multivariate Analysis Line Chart Heatmap
COMPETING TERMS
Parallel Coordinates Small Multiples
RELATIONS
- Broader: Chart
KNOWLEDGE AREAS
Data Visualization Data Science Platform & Tooling
TARGET AUDIENCE
BI Specialist Data Analyst Data Scientist UI-UX Designer Product Owner
EXTERNAL SOURCES
- Wikipedia - Radar chart
- Data to Viz - Caveats and alternatives
- Vega-Lite - Spec and example recipe
- Plotly - Implementation examples in Python
TOP QUESTIONS
When should I use a Radar Chart?
Use radar charts for comparing a few entities across the same small set of metrics, emphasizing relative strengths and weaknesses.
Category: Best Practices
How should I scale variables in a Radar Chart?
Normalize or standardize variables to comparable ranges; otherwise the largest scale dominates the visual impression.
Category: Design
What are common issues with Radar Charts?
They can be hard to read with many variables or series. Overlapping polygons obscure detail and hinder precise comparison.
Category: Mistakes
What are alternatives to Radar Charts?
Parallel coordinates, grouped bar charts, and small multiples often provide clearer comparisons across many variables.
Category: Alternatives
How many variables should a Radar Chart include?
Preferably 3–8 variables. Beyond that, legibility declines quickly.
Category: Guidance
How do I compare multiple entities on a Radar Chart?
Overlay multiple polygons with different colors or opacity, and include a legend. Limit to a few entities to avoid clutter.
Category: How-to
Should I connect the axes in a Radar Chart?
Yes, continuous polygons aid gestalt perception, but ensure gridlines and labels clarify the scale.
Category: Design
Can Radar Charts show change over time?
Use small multiples of radar charts or animation with caution; otherwise time trends are difficult to interpret.
Category: Advanced
How do I handle negative values on a Radar Chart?
Shift or normalize scales to positive ranges, or choose an alternative chart that represents signed values more clearly.
Category: Technique