Proportional symbol map

• Proportional symbol maps use scaled symbols according to the data they represent.
• Proportional symbol maps are suitable when representing point data and you want to show not only distribution, but also spatial variations.
• On proportional symbol maps, the size of the symbols should allow for comparisons to be made without obscuring other essential information 
• Proportional symbols should be placed correctly to show both location and size 
• On proportional symbol maps it is clear to see which values are higher or lower by comparing the size of the symbols.
• Proportional symbol maps can be used for both precise geographical location and geographical area
• You can extract numbers for the map by using the key to estimate the size of the symbols, but it is difficult to calculate the actual value if it isn’t provided.
• The overlap of symbols can mean overcrowding and difficulty interpreting the values as seen on the map close to X and X 
• The size of the proportional symbol can obscure the precise location of the city or can mean less accurate positioning on the maps 
• Developing a proportional symbol map is time consuming, especially calculating the scale for each symbol.
• Reading a proportional symbol map can be subjective or misinterpreted, as some may struggle with differentiating scales.