Accessibility co-design and fatigue/usability protocol — requirements (#419)¶

This is a list of what the protocol must contain. It is not the protocol. It has no protocol ID, no ethics determination and no approved wording, and it authorises nothing: no recruitment, no session, no data collection. The responsible research team writes the protocol (PAPER_EVIDENCE.md "Ethics/publication gate"), freezes it under #425, and obtains the applicable determination before the first participant. Every value written <...> below is a decision that belongs to them and to that determination, not to this file.

Why this file exists. #419 says hands-free defaults are not recommended until structured usability and fatigue evidence exists. The pieces of a protocol are scattered over RESEARCH_PARTICIPANT_TEMPLATE.md, VALIDATION_MATRIX.md, METRICS.md and DATA_SHARING.md, and several elements a fatigue study cannot run without are written nowhere. This file states, per element, what already exists (quoted, so a test can check the quote is still there) and what is absent (so a test can check it is still absent, and force this file to change the day it is not).

This is not a medical study (#419). Nothing here requests a diagnosis or infers capability from a participant; it tests the interaction and the recovery tasks.

Element register¶

file :: phrase in a Provided today cell is a verbatim phrase that must still be in that file. absent :: term in an Absent today cell is a word that must still appear in no other file in this directory; adding it elsewhere is progress, and the way to record that progress is to move the element to Provided today here.

#	Element	Provided today	Absent today	The frozen protocol must still specify
1	Measures	`METRICS.md :: Use a frozen questionnaire/scale in the study protocol` `METRICS.md :: fatigue/change over session` `PAPER_EVIDENCE.md :: participant-reported comfort/fatigue`	`absent :: NASA-TLX` `absent :: Borg`	the named scale(s) and exact item wording; when each is asked — #419 asks for a participant-chosen comfort/fatigue rating before and after; that any item may be declined; the task measures per modality (METRICS.md "Protocol coverage")
2	Session length and exposure	`EVALUATION.md :: Scripted duration: approximately 10–20 minutes.` `RESEARCH_PARTICIPANT_TEMPLATE.md :: Expected duration:`	`absent :: maximum continuous`	maximum continuous exposure per modality, maximum total session, and exposure recorded per modality (a fatigue finding without its exposure is uninterpretable)
3	Rest rules	`RESEARCH_PARTICIPANT_TEMPLATE.md :: You may pause, recalibrate, switch modality or stop.`	`absent :: scheduled break` `absent :: rest break`	whether rests are scheduled or on request, minimum rest between blocks and between modalities, that rest time is excluded from performance time, that taking a rest never costs compensation
4	Stopping rules	`VALIDATION_MATRIX.md :: participant/tester is uncomfortable or fatigued` `RESEARCH_PARTICIPANT_TEMPLATE.md :: You may pause or stop at any time.` `RISK_REGISTER.md :: User cannot stop continuous camera control`	`absent :: facilitator`	the list of conditions on which the facilitator must stop the session (proposed minimum below), who may resume it, and that a stop is recorded as `participant_stopped`, never as a failed trial
5	Adverse-event handling	`RESEARCH_PARTICIPANT_TEMPLATE.md :: Possible discomfort or risk`	`absent :: adverse` `absent :: incident`	what counts as an adverse event or unanticipated problem, the immediate response, who records it and where (never in a public GitHub issue), who must be told under the ethics determination, and follow-up contact
6	Accessibility of the protocol itself	`RESEARCH_PARTICIPANT_TEMPLATE.md :: The study must provide a stop/pause method that does not depend on accurately controlling the experimental pointer.`	`absent :: alternative format` `absent :: large print` `absent :: time pressure` `absent :: untimed` `absent :: read aloud`	alternative formats of the information sheet, consent and questionnaires; an alternative response channel that does not need the pointer under test; untimed, self-paced instructions; the facilitator's assistance rule; seating, camera position and schedule flexibility
7	What consent covers	`RESEARCH_PARTICIPANT_TEMPLATE.md :: Do not bundle optional public release or quotation into one mandatory checkbox` `DATA_SHARING.md :: separate optional permission for anonymous verbatim comments` `RESEARCH_PARTICIPANT_TEMPLATE.md :: Raw consent/contact records are never published.`	`absent :: co-design consent`	the final approved consent mechanism; for co-design sessions held outside #425, either no quotation or a separate quotation consent (#419: "consent for any quote"); re-confirmation after a stop

Proposed minimum facilitator-must-stop conditions¶

These are the conditions the existing documents already imply, collected so the protocol cannot omit one. They are a proposal for the research team to adopt, amend or reject; no numeric threshold is set here.

The participant asks to pause, stop or withdraw, by any channel the protocol offers — an instruction to continue is never given in reply.
The participant reports or shows pain, strain or distress (eyes, neck, face, frustration). (VALIDATION_MATRIX "Stop conditions": uncomfortable or fatigued.)
The independent stop path does not work when invoked. The session ends at once; this is R-05, a release blocker, not a data point. (RISK_REGISTER R-05.)
The pointer or switch performs an unintended action the participant cannot undo or is upset by, or such actions repeat beyond <N, set by the protocol>. (R-03, R-04.)
Recovery from tracking or camera loss re-fires an action. (R-24.)
The task would expose private desktop content; a session uses non-sensitive demo content only. (RESEARCH_PARTICIPANT_TEMPLATE "Possible discomfort or risk".)
Camera permission cannot be granted, or the feature is not implemented on that platform. (VALIDATION_MATRIX "Stop conditions"; a BLOCKED result is evidence.)
Any doubt on the facilitator's part about the participant's wellbeing.

What must be reported, per #419 "Replication dimensions"¶

Number of distinct people, sessions, physical computers, OS/session coverage, camera classes, display scaling/topology, and exposure time per modality. "12 runs" is never summarised without saying which of those it counts.

Two of these cannot be answered from the machine-readable record today, and should not be described as if they could:

Distinct people. The result schema (yazses.eyeeval.schema) has no participant or session field, and the validation registry and coverage page deliberately carry no identity. The research dataset's participant_id and session_id (METRICS.md "Human-study identifiers") have nowhere to live in a community_qa result.
Exposure per modality. Only the face-switch task emits an exposure (scored_duration_s); the Head-Pointer task emits accidental_click_count_total with no exposure to put it over (METRICS.md "Defined, not yet emitted": exposure_s).

Before any hands-free default is recommended¶

Nothing in the repository recommends a hands-free default, and the gate that would allow it is GOVERNANCE.md Gate 7 together with the "Recommendation blockers" of RISK_REGISTER.md: more than one environment and person, a measured false-activation and accidental-click rate, usability and fatigue evidence (R-18, R-23), and no unresolved high-severity risk. The hands-free preset states that every value it sets is provisional, and the user-facing pages that mention a camera feature say it is experimental. tests/test_eye_acceptance_consistency.py checks the second sentence against the feature registry, so it cannot drift back into a recommendation unnoticed.

Community co-design or QA that is not run under #425 stays out of participant-level analysis (DATA_SHARING.md). It can support product decisions and name failures for the controlled study to investigate.