load-bearing pictures · six words at a decision · judged where they are read
Both of these are handed to an assistant constantly, and both fail in a way prose never does. Prose is read in sequence, so a fault shows up as you read. A diagram arrives all at once and microcopy arrives mid-decision, and neither can be judged in a document.
Neither is read the way you write it. That single fact produces every rule below, and it is why both of them survive a review and fail in use.
A bad paragraph is obvious to its writer and a decorative diagram is not, because it looks like an illustration and illustrations are allowed to be pleasant.
People look for: AI diagram prompts, explanatory diagrams, interface microcopy, button labels, and accessible visuals.
One test for a diagram and one for microcopy, and both are ten seconds. Everything else on this page follows from them.
| The picture | Can you say what it carries? | What to do |
|---|---|---|
| Four boxes with arrows between them | Yes. The order, and which steps can happen at once | Keep it. A paragraph would need the reader to hold four things at once |
| A two-by-two of two real decisions | Yes — which combinations exist and which do not | Keep it. This is the shape that a table cannot show and prose cannot either |
| A cycle with five stages | Sometimes — if it really returns to the start | Check. Most cycles in real documents are lines drawn in a circle |
| An icon beside each heading | No | Decoration. Harmless until somebody has to write alt text for it |
| A photograph of people at a meeting | No | Decoration, and it will take a caption, a credit and a description nobody needs |
Six words beside a button are not a sentence in a document. The reader is mid-task, deciding, and has not read the page. So the only useful question is what they are about to do — not what the button does. Save tells them about the system. Save and come back later tells them about their afternoon, and it is the one that stops somebody losing an hour of work to a wrong guess.
A diagram carries a relationship all at once; microcopy resolves one decision at one moment. Both must be judged in context rather than as isolated prose.
Ask for a diagram of the process and you get boxes. Say instead that a reader has to see which two steps can run at the same time, and the shape decides itself. You find out, sometimes, that the answer was a sentence.
Write the alt text before you commission the picture. If the honest description is a diagram of the process, there is nothing in it, and you have saved yourself a reviewer asking what it is for. Day 22 made this an access rule; it is also the cheapest editorial test you own.
Give an assistant the screen, the reader, and what happens after the click, then ask for five options and reject four. Microcopy is one of the few places where generating many and choosing one genuinely beats writing one, because the space is small and you can hold all five in your head.
A generated process diagram looked polished but placed a recurring review as the final step. Redrawing the return path changed the reader's model from delivery to continuous improvement.
A button labelled Continue submitted a long form instead of opening the next step. Naming the consequence changed the label and prevented accidental submissions.
Reviewers could describe the colours and boxes but not the relationship. Writing the intended alt text exposed that the visual had no explanatory claim, so the team redesigned it.
Use a diagram when position, sequence, hierarchy, flow, comparison, or cause is the idea the reader must understand. If the picture merely repeats the surrounding prose or cannot be described more precisely than 'a diagram of the process,' it is decoration rather than explanation.
Describe the reader's question, the relationship the picture must reveal, the items that must appear, the reading order, and the decision the viewer should make afterward. Ask for a labelled structure before visual styling so an attractive composition cannot conceal a weak explanation.
Early alt text forces the author to state what the diagram contributes. If that description has no relationship, change, or conclusion, the visual probably has no teaching job yet. The final alternative text can then be refined for accessibility after the approved diagram exists.
Effective microcopy answers the question present at the decision: what will happen, what the person must provide, whether the action can be reversed, or how to recover. It uses the user's vocabulary, fits the component, and remains accurate in the exact state where it appears.
Neither is read like continuous prose. A diagram is scanned spatially and microcopy is encountered beside a control during an action. Review them at their real size, with neighbouring labels and realistic states; a sentence that reads well in a document can still fail on the screen.
Write the description first, and half the pictures do not get commissioned.