Compare and rank
Radar / spider chart
Plots variables on radial axes and joins them to compare profiles.
- Chart
- Multivariate comparison
- Profile comparison
What it answers
How do performance profiles compare across criteria?
- Shape
- Spokes and profile polygons
- What it shows
- Relative strengths and weaknesses.
Example
The question
How do our two products compare across six qualities customers rate?
Customer ratings out of 5 on six qualities, two products
Illustrative data. It belongs to no company.
When to use it
Use it when
A few profiles with comparable bounded criteria.
Avoid it when
When polygon area or arbitrary axis order drives the conclusion.
How to read it
Read each spoke's scale and compare positions on the same spoke.
Note
Use comparable scales and an intentional axis order.
The data you need
- Layout
- Long table
- Fields
- Profile: text; Variable: text; Value: number
- One row is
- One variable value within one profile. What is the grain?
- Rules
- Define shared variable order and comparable ranges. Do not mix incompatible units without scaling.
- Optional
- Wide alternative: Profile,Speed,Quality.
- Preparation
- Align measurements by observation ID, select relevant variables and handle missingness. Scale or standardise only where the analytical method requires it.
- Units
- Each spoke needs a comparable scale or disclosed normalisation. Polygon area is not an automatic overall score.
Worked example
A: Speed 80, Quality 90; B: Speed 70, Quality 95. With the same scale, A leads speed and B leads quality; do not compare polygon area as a score.
| Profile | Variable | Value |
|---|---|---|
| A | Speed | 80 |
| A | Quality | 90 |
| B | Speed | 70 |
| B | Quality | 95 |