Barcelona Field Studies Centre

Data Presentation: Pie Charts

 

Example: El Raval service structure data for Site 2 with percentage values.

Key
 

Gentrification

Immigrant Services

Local Services

Professional Services

Services of Poverty

Training Centres

Workshops

Map 1: Service Structure in El Raval, Site 2

 

Service Structure Data Summary Chart Site 2

El Raval Site 2
Service Number %
Gentrification 12 11.4
Immigrant Services 16 15.2
Local Services 61 58.1
Professional Services 10 9.5
Services of Poverty 3 2.9
Training Centres 0 0
Workshops 3 2.9
Total 105 100
Size of area: 0.25 x 0.25 kmē = 0.0625 kmē
No. of businesses per kmē = 1,680

 

Chart to show The Structure of Services in El Raval Site 2


Advantages

  • display relative proportions of multiple classes of data

  • size of the circle can be made proportional to the total quantity it represents

  • summarize a large data set in visual form

  • be visually simpler than other types of graphs

  • permit a visual check of the reasonableness or accuracy of calculations

  • require minimal additional explanation

  • be easily understood due to widespread use in business and the media

Disadvantages

  • do not easily reveal exact values

  • Many pie charts may be needed to show changes over time

  • fail to reveal key assumptions, causes, effects, or patterns

  • be easily manipulated to yield false impressions