The von Restorff effect in text marking¶

Theory · All theories
Evidence · 3 claims (2 for, 1 against) · 6 studies (3 causal, 1 quant-synthesis, 1 review, 1 theoretical), q3–q4 · 1 of 6 report an effect size · 2 claims rest on one study

Description¶

The von Restorff effect (also called the isolation effect) is the finding that an item that stands out from its surroundings — through distinctiveness in color, size, or form — is remembered better than items that blend in. Hedwig von Restorff first demonstrated the effect in 1933: when one item in a homogeneous list was made distinctive, recall for that item improved substantially. Applied to text marking, the effect explains how underlining and highlighting function: marked text is isolated against an unmarked background, and readers "tend to study and remember that information better than nonunderlined information."

The mechanism is attentional and encoding-based. Marking increases the probability that the isolated information is attended to during study and receives deeper processing at encoding. Crucially, the effect is relative, not absolute: marking does not add capacity, it reallocates it. What gains salience does so at the expense of the surrounding text, which becomes the "background" and is studied less.

Implications¶

Context¶

Applies to any study or instructional material where learners select a subset of information for emphasis — textbooks, lecture slides, study guides, online course pages
The effect requires a homogeneous background: if everything is marked, nothing is isolated, and the advantage disappears [~M]
The effect's utility depends on whether the marked information is important or unimportant: marking high-relevance content improves test performance on that content, while marking low-relevance content can actively harm learning of the unmarked but important material [~M]
Learner-generated marking (students underlining as they read) is a distinct case from experimenter-provided marking; self-generated marking functions partly as an active-selection strategy rather than a pure isolation effect [~W]

Target Learners¶

College freshmen and other novice readers of academic text, the population in which underlining effects were first studied systematically
Less skilled readers benefit more from externally provided marking, because they are poorer at spontaneously distinguishing important from unimportant information [~M]
Skilled readers may gain little from provided marking and may benefit more from generating their own selections

Target Learning Objectives¶

Recall and recognition of specific, discrete facts and key terms
Text comprehension, when marking is restricted to high-relevance content
Not well suited to integrative or inferential objectives: isolation emphasizes fragments, not relationships between them

Claims¶

Relevancy of emphasis directs attention [+W] — the benefit of marking depends on whether the emphasized information is actually the important information; marking irrelevant content misdirects attention away from what matters
Irrelevant material hurts learning [+S] — the complement of the isolation effect: unmarked background text is processed less, so marking the wrong material effectively deletes it from study
Highlighting and underlining are low-utility study strategies [-M] — Dunlosky et al.'s review rated highlighting as low utility: it reliably improves performance on marked content but shows little benefit or even costs for unmarked content and for transfer

Cognitive Load Theory — marking reallocates limited attentional and working-memory resources; selective emphasis is a load-management device, but over-marking or mis-marking creates a redundancy/salience problem rather than solving one
Information Processing Theory — the von Restorff effect is classically explained as an encoding phenomenon: distinctiveness increases the depth and distinctiveness of encoding, improving retrieval
Dual Coding Theory — visual marking (color, bolding) adds a nonverbal code to verbal content, potentially providing a second retrieval route for marked items

Examples¶

Headings and highlight strategy — applies the isolation effect by pairing structural cues (headings) with selective highlighting, constraining what learners mark to high-relevance content
Attention — marking is fundamentally an attention-direction device; the von Restorff effect describes the payoff of successfully capturing and allocating attention during study
Advance organizers — like marking, organizers pre-select what matters in a text; both work by biasing attention toward high-relevance information before or during reading

Key Sources¶

von Restorff, H. (1933). Über die Wirkung von Bereichsbildungen im Spurenfeld. Psychologische Forschung, 18(1), 299–342.
Nist, S. L., & Hogrebe, M. C. (1985). The effects of high and low relevant text underlining on test performance. (ERIC Document Reproduction Service No. ED265520). https://eric.ed.gov/?id=ED265520
Dunlosky, J., Rawson, K. A., Marsh, E. J., Nathan, M. J., & Willingham, D. T. (2013). Improving students' learning with effective learning techniques: Promising directions from cognitive and educational psychology. Psychological Science in the Public Interest, 14(1), 4–58. doi:10.1177/1529100612453266
Rickards, J. P., & August, G. J. (1975). Generative underlining strategies in prose recall. Journal of Educational Psychology, 67(6), 860–865. doi:10.1037//0022-0663.67.6.860

Page metadata

Field	Value
`type`	`theory`
`title`	`The von Restorff effect in text marking`
`description`	`The von Restorff effect is used to explain how underlining and other text marking function by isolating information against a homogeneous background, directing attention and supporting recall of the marked material.`
`status`	`review`
`canonical`	`True`
`generated`	by `claude/unspecified` on `2026-08-30`
`trust`	unverified — no one has confirmed this page's content

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