Symptom Diary¶
Document — instantiates Intermittent Failure Capture
Lets a person record timing, context, preceding conditions, symptoms, and recovery details for episodic problems that are not directly instrumented.
A Symptom Diary is a human-maintained document in which a person records each episode of an un-instrumented problem — its timing, the conditions preceding it, the symptoms, and how it resolved — one entry per episode, kept contemporaneously rather than reconstructed from memory. Its defining move is to substitute structured human self-report for absent sensors: where no instrument watches the phenomenon, the person becomes the recorder. Its diagnostic power is not in any single entry but in what accumulates — the value compounds as entries pile up into a pattern that the person or an expert can then analyze. The evidence source is a person, and it needs no automatic trigger or system hook to work.
Example¶
Someone gets migraines a handful of times a month, but by the time of the appointment they are gone, and the neurologist has only a vague "they happen sometimes" to work with. They start a symptom diary: each time one begins, they log the date and time, what preceded it (hours of sleep, meals, stress, menstrual cycle, weather, specific foods), the symptoms and their severity, and when and how it resolved — one dated entry per episode. Over two months, twenty entries accumulate. Reviewed together, a pattern surfaces that no single episode revealed: most episodes follow a night under six hours of sleep combined with a skipped breakfast. No sensor recorded any of this; the contemporaneous entries, compared as a set, made an invisible recurrence visible. (Illustrative.)
How it works¶
- A simple, low-friction template captures the recurring fields: timing, preceding conditions, symptoms, and resolution.
- Entries are recorded at or near each episode — contemporaneously — to beat the decay and distortion of memory.
- Each episode becomes one dated, identified entry, keeping episodes countable and separable.
- The accumulated entries are reviewed together, by the person or a clinician, to surface recurring preconditions the individual episodes hide.
Tuning parameters¶
- Template structure — free text versus fixed fields. Structure makes entries comparable but raises friction and the risk of non-adherence; free text captures the unexpected but resists analysis.
- Capture immediacy — logged during the episode versus at day's end. Sooner defeats memory distortion but is more intrusive to daily life.
- Field set — which candidate preconditions to record. Too many fields and the diary is abandoned; too few and the real trigger is never captured.
- Review cadence — how often the accumulated entries are compared.
When it helps, and when it misleads¶
Its strength is that it is often the only capture path when the phenomenon is subjective and un-instrumented, and contemporaneous recording is precisely what defeats the distortion of hindsight. Its named hazard is recall bias — retrospective self-report is systematically warped, and a diary earns its keep only if it records before memory reshapes the event[1]. Its central failure mode is adherence — sparse or backfilled entries reintroduce exactly the recall bias the diary was meant to remove, and a motivated recorder may unconsciously log only what fits a favored theory. The classic misuse is over-reading a handful of entries into a firm cause. The guarding discipline is to keep the template short enough to actually sustain, record contemporaneously, and treat every emergent pattern as a hypothesis to test rather than a conclusion.
How it implements the components¶
Symptom Diary realizes the human-sourced-capture side of the archetype — recording and comparing episodes a person experiences, where instrumentation is absent:
contextual_trace— captures the preceding conditions and surrounding context (sleep, food, stress, weather) that a sensor would otherwise supply.episode_identifier— each episode is a distinct, dated entry, keeping episodes countable and comparable rather than blurred into "it happens sometimes."recurrence_analysis— the diary's payoff is comparing the accumulated entries to find the preconditions common across episodes.
It does not produce a machine state snapshot or a durable protected trace (state_snapshot, evidence_preservation_rule) — those instrumented captures belong to flight_recorder and black_box_log; it does not emit a machine event_log — that is trigger_based_debug_trace's and incident_snapshot's; and it does not decide whether to safely reproduce the episode (reproduction_gate) — that judgment is post_episode_evidence_review's.
Related¶
- Instantiates: Intermittent Failure Capture — supplies human-sourced episode evidence when no instrument is watching.
- Sibling mechanisms: Flight Recorder · Trigger-Based Debug Trace · Incident Snapshot · Rare Event Monitor · Automatic Diagnostic Capture · Post-Episode Evidence Review · Black Box Log
Editorial Notes¶
Form Classification¶
Form family: Record, Log & Register
Rationale: Symptom Diary is defined in the frozen evidence as: Lets a person record timing, context, preceding conditions, symptoms, and recovery details for episodic problems that are not directly instrumented. Its operative deployed or enacted form is therefore Record, Log & Register.
Nearest alternative: Interface, Display & Cue — Interface, Display & Cue can support this mechanism, but the evidence centers the concrete operation described above rather than the alternative family's defining operation.
Review outcome: Adjudicated after independent review; high confidence.
Origin Attribution¶
Primary origin: Medicine & Healthcare
Origin pattern: Single lineage
Present-day reach: Universal
Rationale: Prospective patient symptom diaries are established clinical monitoring instruments.
Related originating lineages:
- Psychology — Self-monitoring records context, perception, and behavior.
Review resolution: The blind reviewers agree that medicine_healthcare is the primary origin and differ only on domain reach disagreement, encyclopedia synthesis disagreement. I preserve every independently explained alternate from both records rather than imposing a numeric cap. I retain single_lineage because the combined evidence shows one traceable formative lineage. The broader reach of universal records portability separately from historical provenance; encyclopedia_synthesis=true preserves the affirmative synthesis judgment where either reviewer identified one.
Encyclopedia synthesis: The exact catalogued form synthesizes established practice rather than reproducing a single standard historical label.
Review outcome: Reconciled after independent review; high confidence.
References¶
[1] Bolger, N., Davis, A., and Rafaeli, E. "Diary Methods: Capturing Life as it is Lived". Annual Review of Psychology 54, 579–616 (2003). Shows how near-event diary reports reduce retrospective reconstruction and recall bias. registry ↩