Product evidence

Your screen has three first things.

The best-aligned of 16 tested layouts was searched twice as fast as the worst — and the eye goes where salience points it. Every screen gets exactly one winner.

Watch this topic on the channel Skip to the squint test

16 layouts tested on 75 participants · every stat linked to its primary source

The research, distilled

Four ideas that should change what you ship

Good alignment can halve visual search time.

Across 16 screen-layout variants tested on 75 participants, the well-aligned, well-grouped layouts were visually searched up to twice as fast as the misaligned ones — a result later replicated in both left-to-right and right-to-left reading directions. The actionable part: shared edges and purposeful grouping are measured; which grid system you use to get there is taste, and we grade it as taste.

Parush, Nadir & Shtub (1998), Int. J. Human-Computer Interaction; RTL replication 2005
Salience steers first fixations — so aim it at the primary action.

Computational salience — size, contrast, color weight against the surroundings — reliably predicts where eyes land first, one of the most validated results in visual attention research. A screen where a promo banner, a badge, and two loud buttons all shout at once isn't neutral: it actively spends the user's first fixation on the wrong thing. Demote everything that competes with the one action the screen exists for.

Itti & Koch (2000) and the saliency-model eye-tracking literature
Consistency measurably cuts time and errors — HCI's oldest replicated result.

Across repeated experiments, consistent interfaces — same term, same placement, same interaction for the same concept — were completed faster and with fewer errors, with the penalty for inconsistency landing hardest on novices and users under load. A one-page pattern sheet that gets enforced captures most of the benefit; a 40-page design system nobody opens captures none of it.

Ozok & Salvendy (2000), Ergonomics; consistency experiments spanning ~100 subjects
"Whitespace improves comprehension by 20%" — the study doesn't say that.

Nearly every version of this stat cites the same 2004 paper, and the paper does not contain the figure. The real whitespace research finds gains in comprehension and comfort that are modest and task-dependent, sometimes at a small speed cost. Whitespace still earns its place — as the tool that makes grouping and alignment legible (the parts that are measured). The percentage is folklore.

Our source-check of the citation chain (Lin, 2004) — the figure appears nowhere in it

The anchor study

They timed 16 layouts. Alignment won, twice over

Study file · Parush, Nadir & Shtub 1998Int. J. Human-Computer Interaction
01 / 03 · The setup
1998. 75 participants visually search 16 variants of the same screen — the aligned ones are searched up to twice as fast.

Parush, Nadir and Shtub built 16 screen-layout variants of the same content, varying how well elements were aligned and grouped, and tested them on 75 participants. The well-aligned, well-grouped layouts were visually searched up to twice as fast as the misaligned ones. A 2005 replication found the same effect in right-to-left reading directions, so it is not a quirk of how one script reads. The measured part is shared edges and purposeful grouping — which grid system you use to get there is taste, and we grade it as taste.

The designSame content, 16 arrangements — only alignment and grouping changed.
Every row that drifts off a shared edge is measurable search time on your screen.
1998Year
75Participants
16Layout variants
2xFaster search (up to)
Parush, Nadir & Shtub (1998), Int. J. Human-Computer Interaction; RTL replication 2005Verified
2x
Verified

Well-aligned layouts were searched up to twice as fast as misaligned ones.

alignment effect · 16 layouts, 75 participants · up to 2x, replicated LTR & RTL
01

See

2x

visual search speed, best- vs worst-aligned of 16 tested layouts

→
02 Every screen gets one winner ✱
→
03

Do

  • Give the primary action strictly higher salience — demote every competitor
  • Put rows on shared alignment edges; group on purpose, not by accident
  • Squint test every screen: blurred, one obvious next action
Data → interpretation → actionThe research + our read

Concepts in action

The squint test: one screen, two ways

Runly, a fictional running app, asking you to upgrade. Same content, same information — the only change is hierarchy. Hit Squint on each version: the After still tells you what to do while blurred. That's the whole test.

Runly ProBEST VALUE
Summer sale — 40% off!!
Training plans10k & half
Live pace zonesIncluded
Yearly price$59.99
Before: the promo gradient, the green button, and the orange button all have top-tier salience — the eye's first fixation is a coin flip, and the money action is one of three shouts. Rows sit on three different alignment edges.

Apply it to your app

Copy the prompt. Paste it into your coding agent. Fix your hierarchy.

This prompt runs the salience-and-alignment audit above on your actual screens — mapping first, changing second, and labeling the one rule that's convention rather than experiment.

You are a senior product engineer applying layout and attention research to my app's screens. Grounding: well-aligned, well-grouped layouts are visually searched up to 2x faster (Parush et al. 1998, 75 participants, 16 layouts; replicated across reading directions), visual salience — size, contrast, color weight against surroundings — reliably steers first fixations (Itti & Koch and the saliency literature), and consistent naming/placement measurably cuts time and errors, hardest for novices (Ozok & Salvendy 2000). One honesty note: "exactly one dominant CTA per screen" is our convention built on the salience evidence, not itself a published experiment — treat it as the default, not a law.

BEFORE YOU CHANGE ANYTHING, map my app and wait:
1. List my main screens (routes/components) and, for each, what you believe the primary action is. I'll correct you — that correction is the spec.
2. Inventory every element with top-tier salience per screen: large type, saturated fills, gradients, badges, animation.
3. Note the alignment containers in use (grids, stacks) and where rows break off them.

THEN audit and show me the plan before coding:
- Per screen: does the primary action have strictly higher salience than everything else? List each competitor and the demotion (smaller, outlined, grayscale, moved).
- Per screen: which elements sit off the shared alignment edges, and which groupings are accidental (unrelated things boxed together, related things separated)?
- Consistency pass: the same action named or placed differently across screens; primary-button style variants. Propose one term, one style, one position each.
- Whitespace: use it to make grouping legible — do not chase any percentage target; the "20% comprehension" stat is a citation myth.
- The squint test is the acceptance criterion: blurred, each screen must still show exactly one obvious next action.

THEN implement with my existing design tokens, smallest diff possible. Show me the diff before applying. Close with a per-screen table: primary action, its salience rank before/after, and what got demoted.

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