---
title: "Who this is for"
description: "The reader of a consumer health screen is anxious, distracted, on a phone, and has not seen the unit before. Every rule in this section follows from that."
url: "https://opsinjs.pensievelabs.org/health/who-this-is-for"
source: "https://opsinjs.pensievelabs.org/health/who-this-is-for.md"
section: "Health"
kind: "health"
evidence: "opinion"
reviewed: "2026-09-02"
reviewer: "content"
aliases: ["layperson", "numeracy", "reading age", "patient audience", "non-clinician"]
implements: ["term", "value", "result-card", "care-card", "disclaimer-note", "scale-input", "questionnaire", "symptom-picker"]
---
> Elements written as `` below are opsinjs documentation
> components. Their attributes are the content: the values they render are
> generated from `tokens/*.json` and `registry/catalogue.ts` and are
> published separately at https://opsinjs.pensievelabs.org/r/index.json and under the Reference
> section.
> Nothing is missing from this page. The data simply does not live in
> the prose.
## What this means [#what-this-means]
The audience for this section is a person without clinical training who is
reading their own result, on their own device, with nobody beside them to ask.
Every rule in the health pillar is a consequence of that reader's conditions
rather than of a general usability principle, which is why the conditions are
stated here rather than assumed.
The same screen is read by that person under two sets of conditions, and both
sets are the design target. The device is the same in both: a four-year-old
Android with the screen brightness turned down and the system font size turned
up two steps, settings that belong to the reader rather than to their fluency
with the metric.
| Reader | What they are doing | Reading window | What the screen must give them |
| --------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | --------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------- |
| **The first-encounter reader.** This reader is not a clinician and has never encountered the unit the number is printed in. | They have opened the app because a notification said a result is ready, and they are standing up on a bus, having waited six days for it and not slept well because of the wait. | Three to fifteen seconds. | What the measurement is, in words they already hold, then the number, the scale it sits on, and what to do next. |
| **The returning reader.** This is the same person six months later, reading a number they now understand well. | They check the figure inside a routine they have built, and they want the figure and nothing else. | Shorter, and spent on the value rather than on the explanation. | The figure, reachable without reading through the explanatory layer. |
What the first-encounter reader takes from the screen inside those three to
fifteen seconds is what they retain, what they relay to their family, and what
they may act on.
The constraint that follows is that one screen serves the first-encounter reader
without delaying or condescending to the returning one.
## The rule [#the-rule]
**Design for a reader who is anxious, interrupted, unfamiliar with the
vocabulary, and using assistive or adaptive settings, and let the fluent reader
skip ahead rather than making the anxious reader catch up.**
Five commitments follow from that rule. Each is an obligation on the screen, and
the last column names where the commitment becomes a hard constraint elsewhere in
this section.
| # | Commitment | Which reader it protects | Where it becomes a hard constraint |
| - | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------- |
| 1 | **No unexplained jargon on a first encounter.** Any clinical term appearing in a user-facing string carries a plain-English expansion in place, on the same screen. | The first-encounter reader, who does not hold the vocabulary. | `Term`, and the glossary at [Plain-English A to Z](../content/plain-english-a-z.mdx). |
| 2 | **A value is rendered with its scale, its unit and a sentence saying what it means.** A value presented without those three cannot be interpreted by a reader who does not already know the metric. | The first-encounter reader, who has no prior figure to compare it against. | [Reference ranges](./reference-ranges.mdx). |
| 3 | **The layout survives the reader's own settings.** The largest system text size, reduced motion, reduced transparency, increased contrast and greyscale are treated as the expected case for this audience rather than as an edge case, because this audience includes readers who already run those settings on every app they use. | Both readers, whose settings persist across every visit. | |
| 4 | **Nothing important is carried once, quickly, or in a single channel.** A reader who looks away mid-animation, cannot distinguish two hues, or has the sound off still receives the message. | The interrupted reader, and any reader whose channel is unavailable. | |
| 5 | **A result is structured to be scanned rather than read in order.** The sequence is the value, its meaning, and what to do now, in preference to a paragraph that has to be read from the start. | Both readers; the returning reader stops at the value, and the first-encounter reader carries on to the meaning and the next step. | |
The last column is empty for commitments 3, 4 and 5 because this page names no
destination for them.
## Why (evidence) [#why-evidence]
Two claims underpin this page, and they sit at different evidence tiers.
The first is uncontroversial and well established across the health
communication literature: adults vary enormously in numeracy and in health
literacy, a substantial fraction of any general population finds probabilistic
and numerical information difficult, and difficulty is poorly correlated with
education or confidence. This page prints no percentage, because population
figures are jurisdiction-specific, instrument-specific and easy to cite
wrongly, and a fabricated or mis-transcribed statistic here would be exactly
the failure this page asks the implementing team to avoid on its own screens.
The second claim is ours and is an opinion: designing for the anxious,
unfamiliar reader costs the fluent reader very little, because the fluent
reader can skip the explanatory layer, so the cost of including it falls mainly
on screen space.
For the presentation of results specifically there is real evidence, and it is
cited on [Reference ranges](./reference-ranges.mdx) rather than restated here.
What would change our mind: a comparison of returning readers with and without
the explanatory layer, showing that the layer measurably slows them or annoys
them enough to reduce engagement with a metric they need to track, would revise
commitments 2 and 5.
Replace the qualitative numeracy claim above with a cited, dated review
once one has been read end to end rather than cited from memory. Tracked on
[Evidence and references](./evidence-and-references.mdx)
.
## Applying it [#applying-it]
Lead with what it is, in words the reader already owns, then give the number
and the scale it sits on.
Print `HbA1c 52` and rely on a tooltip. A tooltip is not available to a
reader on a touch device who does not know there is something to tap, and it
is not read out in the flow of the sentence.
Assume the system font size is set two or three steps above default, and test
at 200%. [Text resizing and zoom](../accessibility/text-resizing-and-zoom.mdx)
describes the check.
Fix the height of a card that contains a clinical sentence. The sentence is
the part that must not be truncated, and it is the first thing a fixed height
clips.
Write the "what do I do now" line even when the answer is "nothing". "No
action needed. Your next test is due in March." states both the next step
and the date it falls due.
Leave a result with no next step. A reader given no answer to "so what?"
supplies one, and what they supply is shaped by how the result made them
feel rather than by the clinical picture.
## Components that implement this [#components-that-implement-this]
{/* Generated from `implements`. Do not restate the list by hand. */}
The audience model is the reason these components have the shape they do: a
result is never a bare number, a term is never left unexpanded, and a card that
carries clinical meaning has a slot for the next step whether or not the
implementing team fills it. Each of them carries `status: shipped` in the
catalogue, which means the component exists and its API may still change.
## What this does not cover [#what-this-does-not-cover]
* **Clinician readers.** A clinician wants density, absolute values, trends and
no reassurance, which is a different surface from the one this section
governs; it is covered in
[Sharing with a clinician](../patterns/sharing-with-a-clinician.mdx).
* **Children as the primary reader.** A child reading their own result, and a
parent or carer reading on someone else's behalf, are separate questions. Both
change consent, tone and vocabulary in ways this system does not yet model.
* **Reading level measurement and the wording itself.** The canonical guidance
for plain language lives in
[Plain-English A to Z](../content/plain-english-a-z.mdx) and
[Health literacy](../content/health-literacy.mdx); this page describes the
reader, not the sentence.
* **Localisation and translation.** Translating a status word without moving it
on the status axis is covered in
[Internationalisation](../handbook/internationalisation.mdx).
## Updates to this page [#updates-to-this-page]