Methodology

What we do — and don’t do

SourceTally is an automated aggregator. It never decides whether an article, claim or outlet is true or false. It does two things: it counts how many independent outlets report the same story, and it collects fact-checks that recognised fact-checking organisations have already published, quoting their ratings with attribution and a link.

Headlines and story grouping

Every update reads the public RSS feeds of 56 news outlets (see Sources). Only the headline, outlet name, time and link are shown; we do not copy article text. Headlines from the last 48 hours are grouped into a story when they share enough distinctive words (an automatic text-similarity rule). Grouping is imperfect: two different stories can occasionally be merged, and the same story can appear twice.

The source count is the number of distinct outlets in a group. Stories with one outlet are labelled “Reported by 1 source so far”. This is a neutral description: exclusives, local news and breaking news often start with a single source. Outlets that share ownership or syndicate wire copy are counted separately, so a count is a measure of reach, not of independent verification.

Fact-checks

We read RSS feeds of 15 fact-checking organisations. Ratings come from, in order: (1) the ClaimReview structured data the fact-checker publishes on its own page; (2) a rating in the checker’s feed (e.g. PolitiFact’s Truth-O-Meter); (3) a rating-style category the checker assigned in its feed. If none exists we show “see the fact-check” rather than guessing. Claimant names are taken only from the checker’s ClaimReview data.

Rating groups

Each checker uses its own scale. For statistics only, we map labels into broad groups by matching words in the label: False / fabricated (e.g. False, Pants on Fire, Fake), Misleading / mixed / unproven (e.g. Misleading, Half True, Missing context, Unproven, Satire), True / mostly true, and Other label. The exact original label is always shown next to each fact-check.

Topics

Topics are assigned by keyword matching on headlines and may be wrong.

Updates

The site is rebuilt automatically (typically hourly). The time of the latest update is shown at the top of every page.