Estimate Waiting Time in a Single-Switch Scan — Free
See how target order changes a single-switch selection wait. Enter the target position, dwell interval and measured activation time rather than guessing which menu feels slow.
The proof surface
A communication-card generator supplies wording. This compares linear scan timing for an existing communication interface without choosing vocabulary or recommending a device.
Why the flat version breaks
Counting the target dwell twice
Activation time already describes selecting the highlighted target.
Optimising without consent
A familiar layout may be more useful than a mathematically shorter wait.
Treating the sum as an average
The total represents one selection of each listed target, not usage frequency.
How to work the scan escapement
This model starts with position one already highlighted. If your device waits a dwell before the first highlight, include that extra delay in activation seconds and document the convention.
Use the actual order in the current menu. Position three has two preceding dwell intervals. Row-column scanning, restart delays and repeated cycles are outside this simple linear model.
Measure a setting the user can activate reliably. A faster interval is not automatically better if it increases missed targets; the result does not measure fatigue or accuracy.
Compare the wait for a frequent target before and after an agreed reorder. Preserve familiar positions unless the user wants a change, and test with their access specialist.
What the scan escapement replaces
| Question | Before | Visible working |
|---|---|---|
| Counting the target dwell twice | Activation time already describes selecting the highlighted target. | Enter each target position |
| Optimising without consent | A familiar layout may be more useful than a mathematically shorter wait. | Use a comfortable dwell |
| Treating the sum as an average | The total represents one selection of each listed target, not usage frequency. | Trial one ordering change |
A local arithmetic aid replaces hand calculation, not expert review. No paid AI service is needed.
Run it on the samples, right here
FIRST-LOAD
Input is processed locally. A state link encodes your inputs in its URL: share only non-sensitive rows. Browser history, clipboard and anyone receiving the link may retain it. Optional AI use below leaves this device; it is not required.
This timing model is not an assistive-technology prescription or an emergency communication system. Trial changes with the user and an occupational therapist or access specialist.
Data note: Everything runs in this browser tab on the scan escapement: your target | position in scan | activation seconds stays on this device, nothing is uploaded, and the reading is rebuilt only when you press run.
Go deeper: the companion app files the same reading as a climbing rung ladder
The article demo above runs without limits. The companion app keeps a local history, exports the rows as CSV, prints the scan escapement reading, and holds your drafts on this device — one free run, then $ 4 one-time for the layer that keeps filing.
The scan escapement reading is complete for free. The optional $4 layer adds print, row CSV and the last five local reading summaries; it does not add hidden answers. Checkout is not configured yet; the article demo remains unlimited.
Open the estimate waiting time in a single-switch scan companionBoundary
This timing model is not an assistive-technology prescription or an emergency communication system. Trial changes with the user and an occupational therapist or access specialist.
What this is built on
- Method: Measure a setting the user can activate reliably. A faster interval is not automatically better if it increases missed targets; the result does not measure fatigue or accuracy.
- All sample records are invented examples. The app does not fetch measurements, policies, files or personal records.
- Google’s official pricing page, fetched 2026-09-27, lists free-tier access including AI Studio. Optional formatting only; limits and availability can change. Free-tier content may be used to improve products. Never paste private records there.
Before: Activation time already describes selecting the highlighted target. After: the scan escapement shows the working beside each named row so the reader can change the assumption and inspect the consequence.
Optional AI formatting, not calculation
For this scan escapement, use the free AI Studio interface only if available to you, with no paid API key. Manual entry completes the same workflow for free. Supply only fictional or non-sensitive notes. Review its output against the source; never paste unresolved questions into the numeric rows.
Format my non-sensitive notes for a scan escapement. Return plain rows only: target | position in scan | activation seconds. Preserve supplied quantities exactly. Do not guess missing values; list questions separately. Do not calculate or add advice. I will check every row before pasting into the local tool.
Accepted schema: target | position in scan | activation seconds. No AI response is executed as code.