Need for graphics
Presentations, reports, lectures, articles, club reports, assignments, theses and similar items can be very boring if they consist only of words with no graphic display material. This can even be true when overhead transparencies in a lecture or seminar presentation, perhaps at a technical conference or business/marketing event, are displayed as words only. Don’t have more than seven short lines of text on an overhead; otherwise it will appear too busy for ease of reading and understanding.
Graphic material in tabular form is easier to read and understand and perhaps remember if the data or information is carefully placed in an order which matches that of the words in the text. Both text and displays should include the most important information first, with the rest of the information discussed and displayed in descending order of importance and finishing with the least important information discussed and displayed last.
Sectors in a pie chart should display the most important or most frequent information in the top right sector position, ie with one radius pointing to the 12 o’clock position with the sector extending in an anti-clockwise direction to the radius at the other end of the sector. The rest of the information should be placed in descending order of importance or frequency around the circle in an anti-clockwise direction with the least important or least frequency finishing back at 12 o’clock. This sequence should be matched in the textual discussion, so readers can easily and quickly follow both the text and its corresponding displays.
Other graphs and charts
In other graphs or charts, place information in an order which makes the most important to be in the most prominent position and the least important to be in the least prominent position, and discuss information in the text in the same order.
There are lots of different graphs and charts and some are more suited to a given situation than others, so choose appropriate ones for your situation. Be aware of graphs where one treatment can obscure another so information is reduced or lost.
If you can, use colour to optimise differentiation of different treatments or categories, but if you can’t, then you will have to choose different shades of grey or different shading, striping, hashing or stippling to indicate differences. If you have a series of graphs showing different effects on the same group of categories, use the same colours or the same shadings etc on all the graphs, again to maintain ease and speed of readability and interpretation between graphs.
The positive influence of colour in presentations reminds me of a joke about a dim-witted farmer who had two horses which confused him because he couldn’t tell them apart, so one day he measured them and found that the white one was 3 inches taller than the brown one.