Von Restorff (isolation) effect
The item that differs from its surroundings is the one noticed and remembered.
Four of the eight page areas.
It also applies sitewide, on every page. See everything at work on Product pages
Four ways to use it, and two to avoid.
- Use one visually distinct primary call to action per screen.
- Highlight one “most popular” option in a set.
- Put sale badges on a minority of products.
- Keep the other items in the group visually alike so the difference registers.
- Avoid: highlighting everything, which makes the effect disappear.
- Avoid: “most popular” or “bestseller” badges that are not true and provable.
A long-standing lab finding that depends on the surrounding items being alike.
It depends on the surrounding items being alike, not on the item being striking.
The memory advantage for an isolated item is a long-standing, often-repeated laboratory finding; Hunt showed it depends on the surrounding items being alike, not on the item being striking. In a lab study of snack-food choices made quickly or under distraction, the more visually prominent item was chosen more often, mainly when preferences were weak.
Three sources, each checked.
Last reviewed
Loses its effect when everything is highlighted. A 'most popular' or 'bestseller' badge must be true and provable, and colour should not be the only cue that marks the difference (WCAG 1.4.1).
This is simply a pointer to check, not legal advice. Seek legal advice before you put this principle into action.