# Source Evaluation & Evidence Synthesis

Grades a body of sources on what each one actually observed, and synthesises only what they support.

## Deliverable

One Markdown document, `evidence-synthesis.md`, in the structure set out under **Output** below. It takes the question written by **Research Plan Design** and feeds **Competitive Landscape Analysis**.

## Required inputs

- **The question the sources are meant to answer** — section 2 of `research-plan.md` is the expected form; any question naming a population, a subject and a period will do.
- **The sources themselves** — the documents, records or pages to be graded, each one reachable rather than only cited.

Without both, stop. A source list with no question cannot be graded, because relevance is a property of the pair. Never substitute a source you were not given for one you cannot reach.

## Optional inputs

- The date each source was published, and the date it was retrieved
- The method each source used, where it states one
- Who funded or commissioned each source
- Sources the requester expects to be dismissed, and why
- Earlier syntheses of the same question, and what they concluded
- The strength of evidence the decision requires before it can be taken

Where a source states no method, no date or no funder, the absence is recorded as `unknown` and counts against its grade. It is never filled in from the source's reputation or from what sources of that kind usually do.

## Execution

**1 — Fix the question and the inclusion rule.** Restate the question, then write the rule that decides whether a source is in or out. Apply that rule to every source before reading any of them for content, so that inclusion is never decided by whether a source agrees with the expected finding.

**2 — Classify each source by what it observed.** Primary if it reports observations its own authors made; secondary if it reports observations someone else made; tertiary if it summarises a secondary account. A source that observed nothing and cites no one is opinion, and is labelled as such rather than quietly dropped.

**3 — Trace each claim to its origin.** Follow the citations back. Where several sources rest on one original, record them as a single line of evidence with that origin named. Repetition across sources is not corroboration, and counting it as corroboration is the most common failure in synthesis.

**4 — Grade each source on what it actually did.** Record the method, the population it observed, the period it covers, who funded it, and the distance between what it claims and what its own method could establish. A claim wider than the method that produced it is recorded as overreach against that source.

**5 — Record the disagreements.** Where sources conflict, state what they conflict about, what evidence each side rests on, and whether the conflict is about observation, about method or about interpretation. Disagreement is a finding; averaging it into a middle position destroys it.

**6 — Synthesise only what the body supports.** Each statement carries the sources behind it, the lines of evidence it rests on, and the strength of those lines. A claim no source supports does not appear, however plausible it is and however firmly the requester expects it.

**7 — Name what the evidence cannot settle.** The parts of the question the supplied sources do not reach, and the kind of source that would reach them.

## Output

`evidence-synthesis.md`, in this order:

- **1. Question and inclusion rule** — the question, the rule, and the date it was applied
- **2. Source register** — one line per source: title or identifier, author or publisher, date published, date retrieved, and `primary`, `secondary`, `tertiary` or `opinion`
- **3. Grades** — per source: method, population observed, period covered, funder, and any overreach found
- **4. Lines of evidence** — the independent origins, and which sources trace back to each one
- **5. Excluded sources** — the source, the rule it failed, and who supplied it
- **6. Findings** — one statement per line, each with the sources behind it and the strength of the evidence
- **7. Disagreements** — what is disputed, what each side rests on, and whether it is observation, method or interpretation
- **8. What the evidence cannot settle** — the part of the question left unreached, and the kind of source that would reach it
- **9. Open questions** — the question, what it blocks, who can answer it

## Validation

The synthesis is ready when all of these hold:

- Every statement in section 6 cites at least one source listed in section 2
- Every source in section 2 carries a class and a date, or `unknown` where none was stated
- Sources that share one origin appear as a single line of evidence in section 4
- Section 5 lists every excluded source with the rule it failed
- Section 7 is either non-empty or states explicitly that the sources did not conflict
- No figure appears in section 6 that is not carried by a cited source

Fail the run if a finding cites no source, or if repeated citations of one origin are counted as separate lines of evidence.

## Failure handling

- **No sources supplied** — stop. Report that synthesis has nothing to synthesise, and name the kind of source the question requires.
- **A source cannot be reached** — list it in section 2 as `unavailable`, exclude it from section 6, and record in section 9 who can supply it. Never summarise a source from its title or from another source's description of it.
- **Every source traces to one origin** — deliver the synthesis with a single line of evidence in section 4 and state plainly that the body of evidence is one observation repeated. Do not present it as agreement.
- **Sources contradict each other flatly** — record both positions in section 7 with their grades, and report the question as unsettled by this body of evidence. Do not resolve it by preferring the better-known source.
- **Partial material** — synthesise what the supplied sources support, mark the rest `INCOMPLETE — pending <source>`, and deliver. A synthesis that names the sources it lacks is usable; one that closed the gap by inference is not.