Compare each axis before making an overall judgement; the largest polygon is not automatically the best place.
A radar chart places several axes around a centre. Plot each score on its axis and join the points to form a profile. In this example, every axis runs from 0 to 5 and a higher score means a more favourable condition.
Site A scores higher for transport and toilets. Site B scores higher for shade and seating. The overlapping profiles make this trade-off visible. Explain what each score means: a rating of five for shade should come from an agreed rule, not an unexplained impression.
Keep scales and directions consistent when comparing profiles. Mixing temperature in degrees with satisfaction on a five-point scale creates arbitrary shapes unless values are meaningfully standardised and the method explained. Reversing one axis can also invert the apparent conclusion.
The polygon's area is sensitive to axis order, scales and the measures chosen. It is not a direct measure of liveability. An overall recommendation requires justified priorities and evidence of who uses the place. Residents who need rest stops may value seating more than a researcher's equal weighting assumes.
Step by step
Read the scales
Check the centre, outer limit and whether high values are favourable.
Compare axes
Identify strengths and weaknesses using exact scores.
Explain priorities
Link the judgement to residents' needs rather than polygon size.
Worked example: A qualified recommendation
"B better meets the stated need for shaded resting places, scoring 4 for shade and seating versus A's 2. However, users dependent on transport may prefer A. Check the affected residents' priorities before treating either site as best overall."
Watch out for this
The radar polygon's area is an objective overall score.
Area depends on axis order, scales and selection. Evaluate the individual measures and any weighting explicitly.
Check your understanding
What must be checked before overlaying two radar profiles?
- Whether the colours are equally bright.
- That axes, units, scale directions and scoring rules match.
- That both profiles enclose the same area.