Figure next to its text

Claim: the words that explain a figure, a formula or a block of code sit beside or inside it: not on another page, not below the fold.

• Grade: measured for figures and formulae, in learning material for novices; for code, applied by analogy.
• Evidence: learning science (strand 5), typography and layout (strand 6).
• Check: figure-captions: every image has alt text, and every drawn figure has words right beside it. The alt text says what the figure shows, never its file name or a word for its kind (figure-alt, exact).
• Reader styles: none override it.

What it asks

• Labels on the figure rather than in a legend; the caption is a sentence that says what to see.
• The prose refers to the figure and does not describe it again.
• A formula's symbols are named in the sentence just before it.

Why

Placing words next to the picture they explain raised learning, d = 0.72. Learners gained more from complex material than from simple (0.78 against 0.28, the latter from 7 effects whose interval reaches zero). Every learner studied was a novice (Ginns 2006, a meta-analysis). A split figure makes the learner hold one part in memory while searching for the other (split attention; Ayres 2014).

Limits

The effect is measured on learning material; for reference material read by experts it is untested. The studies placed words by diagrams, formulae and worked examples; none placed them by code, so code is included by analogy.