Figure 1. Example 1 of a pictogram
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A pictogram uses pictures to represent frequencies. It can be defined as shown below.
| Pictogram “A diagram in which frequency or quantity is represented by symbols that are small images of the objects or material being counted” (Upton & Cook, 2014, p. 324). |
In Figure 1 an example of a pictogram.
Figure 1. Example 1 of a pictogram
In the example two people have as a favourite shape round, four a square and three a triangle.
Sometimes one picture represents multiple frequencies, and then only part of the picture is shown if it is less (e.g. one and a half stick figure for 1500 people). An example is shown in Figure 2.
Figure 2. Example 2 of a pictogram
In Figure 2 one person represents 1 billion people. In 1850 it seems there were 1 billion people, but it is hard to tell how many perople there were in 1650. It is less than 1 billion, but the exact number is not clear. If the image used is not symmetrical it can be hard to tell, especially if the image is not symmetrical.
In some cases a single image is used and then scaled to show an increase or decrease. Often however the increase/decrease shown is misleading, since often both dimensions (width and height) are scaled, instead of the area. If for example a square is used of width 1 and length of 1, and the increase is twice as high, then the other square might be shown as 2 by 2, which increases the area by a factor of 4 (not 2). To precisely increase the area is also more difficult when the image is not a 'nice' shape (e.g. a square, sphere, triangle, etc.).
Although a pictogram might look nice, when used for large numbers it becomes either unreadable (too many images) or a loss in detail of the frequency it represents occurs (such as in Figure 2). It is often therefor seen in marketing, but not very often in proper research.