Presenting Data

Presenting Data

1. Factors to consider when selecting a technique to present data

   • Scale/Interval
   • Location
   • Size of symbol
   • Shading
   • Colour
   • Lettering
   • Dimension
   • Key
   • Map scale

2. Tables

   • Simple but effective
   • Shows lots of data
   • Limited visual impact

3. Diagrams

   • Covers a range of images
   • Pictograms use pictures and symbols to represent the values of the data

4. Charts

   • More precise than tables or diagrams.
   • Vast variety.
   • These are forms of proportional symbols.

5. Types of proportional symbol

   • Bar Chart: uses most data, however width can mislead.
   • Pie Chart: very visual, however colour distracts and too many sectors may become confusing.
   • Divided Bar: show constituents of a whole eg. jobs, however it's not easy to compare.
   • Rose or Star: use to show direction, however it is hard to read.
   • Proportional circle, square, diagram: used to show direction, however, not easy to compare.
   • Proportional sphere, cube, pyramid: used to show direction, however, not easy to compare.

6. Graphs

   • Normally refers to line graphs but it can apply to scatter graphs or cumulative frequency graphs as well.
   • Ideal for continuous data or when looking for patterns or trends between two or more variables.

7. Maps

   • Simplest form of displaying over space.
   • Relevant features and data can be marked on.
   • An OS map is in reality a display of the spatial pattern of a vast range of data, much of which has been reduced to a symbol.
   • All need a scale, title and north arrow.

8. Isopleths/Isolines:

   • Lines that represent the same value at the points in an area through which it passes. Issues: doesn't give location of the points.

9. Chloropleths

   • Density maps where areas are shaded in to represent the average number per unit area.
   • Common as gives a quick visual impression of patterns.
   • Colours are difficult so should be avoided. They don't show progression.

10. Located symbols

    • Many of the proportional symbols can be placed on a base map to show patterns/
    • Overlays are effective to compare patterns provided the same symbols at the same scale are used.

11. Flow Lines

    • Used to show the volume, frequency and make up of movements along routes, such as roads and river Channels.

12. Trip Lines

    • Are a type of flow line that they show direction and volume but are straight line drawings from origin to destination.

13. Pictorial Displays

    • Useful ways of showing qualitative data by locating images or photos on a base map.

14. Sketches

    • Recording an impression of an area as well as showing its main features.

15. Photographs

    • Images of an area/location.

16. Types of located symbols

    • Dot Maps: simple, clear location. However, scale is hard.
    • Proportional Circles: deals with large numbers. However, size is difficult to measure out.
    • Combined Dots and Circles: good where high and low values. However, they can be confusing as scale is complex.
    • Located Bars: simple, quick and easy to compare. However, bars often extend over boundaries so confusing.