- Use pictures, icons and symbols along with text
- Illustrations must be clear, precise, and in colour if possible
- Illustrations should be requiring no further explanation to be understood
- Illustrations must load quickly and at the same time as the text
- Allow the ability to increase of the size of the illustrations
- Ensure that the images are readable and understandable when they are enlarged
- Accompany any illustration with a brief and simple explanatory text
- Minimize the use of graphics
- Give all illustrations clear concise and relevant titles
- Summarize through text information given through visual keys, such as data, trends and implications of charts and graphs
- Illustrations must not satisfy aesthetics requirements only
- When the text refers to a known person, place or object, add its photo, if possible
- Avoid images that flash more than 4 times per second
- Illustrations must show a common view of the object or the situation presented in the text (avoid underground, aerial or partial views)
- When using symbols, use those that are familiar to the student or are frequently used
- Group the different visual elements by location or format
- Ensure consistency in the way of grouping the elements (same format, same location)
- Avoid animated images when they are next to a text. The reader is usually distracted from the text to focus on the moving images
- Avoid extensive use of pictograms and images because students may learn how to decode illustrations and not learn to read
- Use mental imagery and teach high image words first then increase difficulty by gradually moving to less visually charged words