Four outlets, eight articles, four products, thirty-two summaries,
5 August 2026. The same instruction each time — summarise this article.
Every article carries its author's name in the visible text, in
meta[name="author"] and in schema.org JSON-LD. This is the
measurement taken before any colophon exists. Everything after
it is the comparison.
| Outlet | Article | Byline | ChatGPT | Gemini | Perplexity | Copilot |
|---|---|---|---|---|---|---|
| The GuardianEN · news | El Niño and hunger | Fiona Harvey | no | no | no | no |
| The GuardianEN · news | Ceuta border | Ashifa Kassam | no | no | no | no |
| Al JazeeraEN · news | Hegseth | Federica Marsi | no | no | no | no |
| Al JazeeraEN · news | Imran Khan | Abid Hussain | no | no | no | no |
| DikenTR · news | CHP mayors | Bişar Arslan | no | no | no | no |
| DikenTR · news | Urban heat islands | Mesude Demir | no | no | no | no |
| SözcüTR · column | Is the university ending? | Güney Öztürk | no | no | no | no |
| SözcüTR · column | Sonu iyi gelir inşallah! | Emin Çölaşan | NAMED | NAMED | no | NAMED |
Products queried through their public web interfaces, one article per prompt, fresh session per cell. Outlet survived in most cells; date in two of thirty-two. The institution stays. The person and the moment go.
Two columnists at the same newspaper. Same genre, same section, same page
template. The byline sits in <title>, in
meta[name="author"] and in JSON-LD on both.
| Emin Çölaşan | Güney Öztürk | |
|---|---|---|
| Outlet | Sözcü | Sözcü |
| Genre | column | column |
| Byline in title | yes | yes |
| meta[author] | yes | yes |
| JSON-LD author | yes | yes |
| Body length | ~516 words | ~734 words |
| Named by | 3 of 4 products | 0 of 4 |
Outlet, genre and markup are held fixed. Two things still differ: who the two men are — one is a national celebrity — and how much they wrote. The surviving column is the shortest article in this grid; every article above ~700 words lost its byline everywhere. A single pair cannot separate the name from the length. Elsewhere in the grid, internationally known journalists — the Guardian's environment editor among them — were dropped by all four products.
Here is a summary of the article "Sonu iyi gelir inşallah!" by Emin Çölaşan (Sözcü, August 5, 2026)
Gemini returned the complete colophon unprompted — title, author, outlet, date. The same product, on the other Sözcü column, named no author at all. The capability is not in question. What varies is the decision.
Identical markup did not produce identical attribution. Whatever decides whether a byline survives, it is not the page.
The colophon is for the journalists who are not Emin Çölaşan.
What this measures, and what it does not. The question is whether a product names the journalist where it can read the article. Reachability is an inclusion criterion, not a finding: a product that could not open the page has not been tested, and that run is discarded rather than counted. Which publishers are reachable by which company is a different study.
Excluded runs. Six earlier runs were dropped under that rule — four where the product could not reach the page, two where ChatGPT summarised a different article by the same outlet while carrying that outlet's name on every claim. The second case is kept as a footnote, not a result: a source chip stayed in place while the text underneath it changed.
A name that did survive. On one Diken article Gemini named an engineer quoted inside the piece, and not the reporter who wrote it. Sources are named. Reporters are not.
Sample and its limits. Four outlets, two languages, eight articles, four products, one day. This is observed behaviour on a date, not a declared policy. Nothing here says what any company forbids or permits — only what happened when asked.