Before deciding to use a diagram, identify the user need. Consider if the user need can be met solely by clearly written text.
Questions to ask yourself
- What is the message you would be trying to communicate with a diagram?
- Would a diagram help the user to understand the subject or would it repeat what is already in the text?
- Can the message be communicated as text or a table instead of a diagram?
If you have too much information to communicate, a diagram is unlikely to be useful to users. If you can describe the diagram in a short paragraph, use text instead.
When not to use a diagram
- When your diagram raises as many questions as it answers.
- When there is too much text in the diagram – this can be difficult to read or scale for different devices.
- When the diagram is so complicated that it requires significant time and resource to create; the more straightforward it is, the more useful your diagram will be.
- If the information could be organised as a table – this is a more accessible format.
- If your content is updated regularly – it is easier to change text than it is a diagram.
If you are unsure whether a diagram would meet your users’ needs, contact the design team at firstname.lastname@example.org for guidance.
When diagrams meet the user need
Diagrams will meet user needs if they:
- show a process or relationship without needing further explanation in text or footnotes
- communicate information in a more succinct and direct way that can replace several paragraphs of dense text
- can be understood by someone not familiar with the subject matter
Include alt-text for those unable to view the diagram.