Official Statistics - Official Statistics Presentation

Official Statistics Presentation

Official statistics can be presented in different ways. Analytical texts and tables are the most traditional ways. Graphs and charts summarize data highlighting information content visually. They can be extremely effective in expressing key results, or illustrating a presentation. Sometimes a picture is worth a thousand words. Graphs and charts usually have a heading describing the topic.

There are different types of graphic but usually the data determine the type that is going to be used.

• To illustrate changes over time, a line graph would be recommended. This is usually used to display variables whose values represent a regular progression.

• For categorical data, it is better to use a bar graph either vertical or horizontal. They are often used to represent percentages and rates and also to compare countries, groups or illustrate changes over time. The same variable can be plotted against itself for two groups. An example of this is the age pyramid.
• Pie chart can be used to represent share of 100 per cent. Pie charts highlight the topic well only when there are few segments.
• Stacked bar charts, whether vertical or horizontal, are used to compare compositions across categories. They can be used to compare percentage composition and are most effective for categories that add up to 100 per cent, which make a full stacked bar chart. Their use is usually restricted to a small number of categories.
• Tables are a complement to related texts and support the analysis. They help to minimize numbers in the description and also eliminate the need to discuss small variables that are not essential. Tables rank data by order or other hierarchies to make the numbers easily understandable. They usually show the figures from the highest to the lowest.
• Another type of visual presentation of statistical information is thematic map. They can be used to illustrate differences or similarities between geographical areas, regions or countries. The most common statistical map that is used is called the choropleth map where different shades of a colour are used to highlight contrasts between regions; darker colour means a greater statistical value. This type of map is best used for ratio data but for other data, proportional or graduated symbol maps, such as circles, are preferred. The size of the symbol increases in proportion to the value of the observed object.