Example: El Raval service structure data for Site 2 with percentage values.
Map 1: Service Structure in El Raval, Site 2
Service Structure Data Summary Chart Site 2
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
