Source check

Research goes wrong at the number level: a stale figure, a wrong unit, a restated value, a quote that was paraphrased. This skill checks each one against where it came from.

Workflow

1. List every claim that can be checked

Pull out each number, date, ratio and quotation, with the sentence it sits in.

2. Find the primary source

Prefer the original: a filing (annual and quarterly reports, ESEF or XBRL data), a central bank or statistics office, an exchange, the company's own investor pages. An article about a figure is a pointer to the source, not the source.

3. Record the evidence

For each claim: the value, the unit, the period the value describes (as of), when you retrieved it, and exactly where it sits (URL, page, table, field).

4. Compare

Mark each claim match, mismatch, cannot find or derived. Look for the usual traps:

• percent versus percentage points;
• thousands versus millions, and the currency;
• fiscal year versus calendar year;
• restated figures: for a historical question, use the value that was known at that time;
• adjusted versus unadjusted prices;
• delayed data presented as current.

5. Recompute what was derived

Growth rates, margins, ratios, per-share figures: recompute them from the inputs and compare.

6. Check quotations

A quote must match the source word for word. A paraphrase is not a quote and must not sit inside quotation marks.

7. Give a verdict

The research passes only if every number is matched or correctly derived. Otherwise list what failed and what was not found.

Output

| # | Claim | Value in text | Value in source | Unit | As of | Source location | Result |
|---|---|---|---|---|---|---|---|

**Verdict:** pass | fail
**Not found:** <claims with no primary source>
**Data age:** <oldest as-of date and what it feeds>

Rules

• Never fill a gap from memory. If you cannot find the source, write "cannot find".
• Never round or adjust to make a number match.
• Secondary sources may point you to the primary one but never settle a claim.
• Say how old the data is. Stale data that feeds a conclusion is a finding, not a footnote.
• One unsourced number is enough to fail the check.