[ Public ]
FrameworkMetric vocabulary, limits, and screening structure.ReportsReviewed public case histories and score interpretation.CasesEditorial comparisons built from reviewed public reports.Icon setsCanonical provider coverage linked to public reports.Public-service contextOne high-risk coverage context for shared icon decisions.AboutProject origin, creator, and operating boundaries.[ Case history 001 / Signage + AAC baseline ]
The toilet drawing scores better because it gives users a concrete referent. It still does not become universally transparent. The case shows why public signage should satisfy AAC-style transfer before it asks users to rely on convention.
Finding a toilet is often urgent. For AAC users, children, travellers, and people in cognitive distress, a sign that needs decoding is a sign that fails.
[ WC unisex signage ]
The sign shows two restroom figures separated by a vertical divider. It indicates inclusive restroom access through convention, but it does not show a concrete toilet or fixture.
PCS
0.46
STS
0.30
CRI
0.63
NTR
0.89
[ Toilet fixture pictogram ]
The fixture drawing gives a concrete restroom referent, with perceptual convergence at 0.86. It improves direct transfer, but still needs context or text support for some viewers.
PCS
0.66
STS
0.66
CRI
0.48
NTR
0.60
[ Metric movement ]
The toilet fixture improves the central comprehension metrics and perceptual convergence. It does not erase support needs, because signage still has to move from object recognition to restroom access.
| Metric | WC unisex | Toilet | Reading |
|---|---|---|---|
PCS Composite clarity estimate | 0.46model | 0.66model | The toilet fixture moves from intervention-prone toward support-sensitive, because the visible object better matches the restroom concept. |
STS Direct meaning transfer | 0.30model | 0.66model | Semantic transparency more than doubles. The fixture is easier to map to toilet access than gendered figures with a divider. |
CRI Competing misreading risk | 0.63model | 0.48model | Confusion risk falls, but not to zero. The fixture can still need placement or a text cue to resolve restroom access. |
NTR AAC-style transfer risk | 0.89model | 0.60model | Neurocognitive transfer risk drops sharply. This is the main reason the fixture is a stronger signage base. |
PCV Perceptual convergence | 0.79model | 0.86model | The fixture also has higher perceptual convergence: viewers can settle on a shared visual object before they solve the full restroom meaning. |
Provenance legend
machine machine-deterministic or measured inputs; model model-estimated screening value; human human-reviewed judgement.
[ Editorial verdict ]
It carries a more concrete referent, higher semantic transparency, lower confusion risk, and lower neurocognitive transfer risk. Better is not sufficient: with NTR still at 0.60, it can fail a meaningful share of viewers, which is exactly why pre-testing matters.
The figures and divider require convention: users must infer restroom access and inclusive availability from a social code.
They are the lowest-friction test for whether a symbol can transfer meaning before labels, location, and learned signage rules help.
[ Evidence notes ]
The external literature validates the comparison method and the direction of the effect, not the specific values above, which are model estimates pending human testing.
[ W3C WCAG ]
WCAG frames labels and text alternatives as a way to make non-text information available across modalities. That supports the case for pairing icons with text, but it also confirms that the text layer is a linguistic layer.
[ ISO 9186-1 ]
The public-symbol testing standard explicitly treats comprehensibility without supplementary explanatory text as the preferred target. Supplementary text becomes necessary when the symbol cannot communicate the intended message on its own.
[ AAC research ]
AAC literature uses iconicity and transparency to describe how strongly a pictogram relates to its referent. That is the same pressure PictoClarity applies to signage: the graphic should make the meaning easier before context finishes the job.
[ AAC cross-culture ]
Cross-cultural AAC work reports that different cultural and linguistic groups can perceive graphic symbols differently. That does not weaken the AAC baseline; it explains why signage should test transfer instead of assuming universality.
[ Next reading ]
A restroom sign can rely on placement, architecture, and text. Those cues are useful. They should not become the reason to skip the basic transfer test.
A label remains the immediate accessibility support. WCAG 1.1.1 asks non-text content to have a text alternative that serves the same purpose. That support matters, but it is still language. It brings vocabulary, localization, literacy, and cultural assumptions back into the reading.
For a public toilet concept, the concrete fixture moves the symbol closer to AAC-style access. The unisex version may still be needed for policy and inclusion, but the pictogram should still carry the meaning as far as possible before a label completes it.