Charts (Cambridge (CIE) IGCSE Geography): Revision Note

Bar Chart

• A bar chart is the simplest form of displaying data

• Each bar is the same width but can have varying lengths

• Each bar is drawn an equal distance apart (equidistant)

• The data is discrete data

• Bar graphs are useful for:

  • Comparing classes or groups of data

  • Changes over time

Compound or Divided Bar Chart

• The bars are subdivided to show the information, with all bars totalling 100%

• Divided bar charts show a variety of categories

• They can show percentages and frequencies

Population Pyramid

• The characteristics of a population—the distribution of age, sex, ethnicity, religion, etc.—are known as the population structure

• The two main components of age and sex can be shown on a population pyramid

• This is a graphical illustration of the distribution of a given population, grouped by age and gender

• It can be used to represent a population of any region, city, country or even the world

• As the population grows the shape of the pyramid changes 

• The population pyramid can be used to identify the following groups:

  • Young dependants 

  • Old dependents 

  • Economically active (working population)

  • Dependency ratio 

Pie Chart

• Used to show proportions, the area of the circle segment represents the proportion

• A pie chart can also be drawn as a proportional circle 

• Pie charts can be located on maps to show variations at different sample sites

• The percentage of the pie chart must add up to 100%

• To calculate degrees of the pie chart (which totals 360°), divide the percentage by 100 and then multiply by 360

• Each segment should be a different colour

Rose diagram

A rose diagram is a type of radial graph

• It uses compass points for the axis directions

• Can be used for data such as wind direction, noise or light levels

Histograms

• Histograms show continuous data

• Always use a ruler to draw the bars

• All bars should be the same width 

• The top of the bar should reach the number on the side of the graph that is being represented

• There should be no gaps; all bars should be touching

• Ensure all axes are labelled and that the graph has a title