Measured by us · Nov 13, 2026 NewsShorts-Bench · Stage 10: Faithfulness check

Can AI catch a news clip that misleads out of context? 10 judges tested

Result

Gemini 4 Argon leads (macro-F1 0.847). Open GLM-5.2 is within about 3 points with the fewest false alarms on fair trims. The MiniCheck fact-checker finds 2% of misleading cuts: grounding checkers can't see a context cut.

Data

162 clips

constructed traps on 54 real stories

Compute

Hosted APIs

MiniCheck on CPU

Truth

By construction

one clip edge moved

Metric

Macro-F1

95% CI, bootstrap by story

Macro-F1, misleading vs fair · higher is better

0.30.40.50.60.70.80.91.0Gemini 4 Argon0.847Gemini 3.5 Flash0.816GLM-5.20.814Gemini 3.8 Flash0.778Gemini 4 Argon, 2nd prompt (v…0.772gpt-oss-120b0.661DeepSeek V4.1 Flash0.646Gemma 4 26B-A4B0.567Gemini 3.5 Flash-Lite0.521MiniCheck Flan-T5-Large (fact…0.407

Dot = measured, whiskers = 95% CI, dashed line = best. Overlapping intervals: the ranking is not significant. Hollow dot = reference row (agreement ceiling or baseline), not a contender.

ModelMacro-F195% CIKappaMisleading recallFalse alarm, fair trimsECEMacro-F1, validateds / item
Gemini 4 Argonclosed0.8470.785–0.9040.700.720.090.100.9577.9
Gemini 3.5 Flashclosed0.8160.748–0.8750.630.670.090.070.8934.4
GLM-5.2open0.8140.742–0.8780.630.650.070.090.9266.3
Gemini 3.8 Flashclosed0.7780.702–0.8420.570.540.040.090.8936.5
Gemini 4 Argon, 2nd prompt (validator)closed0.7720.701–0.8330.550.540.060.12 - 5.7
gpt-oss-120bopen0.6610.590–0.7370.350.830.430.210.71740.5
DeepSeek V4.1 Flashopen0.6460.570–0.7190.320.350.070.160.6413.3
Gemma 4 26B-A4Bopen0.5670.498–0.6340.200.200.040.230.4341.3
Gemini 3.5 Flash-Liteclosed0.5210.454–0.5910.150.130.020.240.5051.4
MiniCheck Flan-T5-Large (fact-checker)baseline0.4070.384–0.438-0.040.020.060.270.4163.6

The hookLink to this section

A clip is an excerpt, so every word in it was really said. That is exactly why it can mislead: end a clip one sentence before "...but the court overturned that ruling" and the viewer leaves believing the opposite of the story.

Fact-checking models can't catch this. They ask "is this supported by the source?", and the answer is always yes. We built 162 traps from real news to measure which judges can catch it. The standard support checker finds 2% of them.

The setup, in one pictureLink to this section

150 real bulletin stories (40 s+, 5+ sentences)
   │ generator returns three whole-sentence clips per story:
   │   faithful · trimmed (shorter, still fair) · misleading (ONE edge moved)
   │ 94 stories declined: no honest misleading cut exists
   ▼
54 stories · 162 clips · truth by construction
   ▼
10 judges see the full story + one clip, shuffled, and answer: misleading?
   ▼
macro-F1 (95% CI, by story) · recall on traps · false alarms on fair trims

The "trimmed" clip is the hard negative: missing detail isn't misleading, and a judge that flags every short clip is useless.

What the numbers sayLink to this section

  • Gemini 4 Argon leads at macro-F1 0.847 (95% CI 0.785–0.904).
  • A good open verifier exists. GLM-5.2 scores 0.814, within about 3 points with overlapping intervals, and has the fewest false alarms on fair trims (7%). It rarely blocks a good clip.
  • The fact-checker is blind by design. MiniCheck says the story supports 98% of misleading clips, which is literally true. It catches 2%.
  • Judges split into over-flaggers and under-flaggers. gpt-oss-120b catches 83% of traps but flags 43% of fair trims. DeepSeek V4.1 Flash, Gemma 4 26B and Gemini 3.5 Flash-Lite are polite and miss 65–87% of traps.
  • Being good at one text task doesn't predict this one. DeepSeek ranked stories well in stage 9 and judges poorly here.

The most common trap was a dropped correction or contrast (26 of 54), then a dropped outcome (10) and a dropped qualifier (9).

The dirty laundryLink to this section

  • The generator disagrees with itself. The same model built every trap, yet under a second prompt it calls only 54% of its own misleading clips misleading. Out-of-context distortion is a judgment call, which is why absolute accuracy needs human labels.
  • Most stories can't be made misleading by moving one edge: 94 of 150 were declined. Good news for a pipeline that cuts whole sentences inside one story.
  • Text only. Judges read transcripts; pictures can also add or remove context.
  • Operational traps: gcloud handed back near-expiry tokens and 116 calls got 401s; some calls hung until a 30-minute timeout. Tokens now refresh every 5 minutes and timed-out calls are retried.

The recipeLink to this section

  1. Never use a grounding fact-checker to verify clips. It can't see a context cut.
  2. Use a reasoning judge that sees the whole story. GLM-5.2 is our open verifier: near the frontier, fewest false alarms.
  3. Score false alarms on fair-but-shorter clips, or you'll pick a judge that blocks everything.

What's nextLink to this section

Human-labelled traps, transfer tests on public misinformation sets, and a judge that sees pictures as well as words.

Method & environment
  • Question: A clip is a contiguous excerpt, so every word in it was really said. Can a verifier tell when moving one edge of the clip changes what a viewer would believe?
  • Compute: Hosted APIs + local CPU (MiniCheck)
  • Method: For each story a generator returns a faithful clip, a shorter fair trim and a misleading clip made by moving exactly one edge. Each judge sees the full story and one clip at a time, in shuffled order. The validated subset is where a second prompt agrees on all three clips.
  • Numbers are imported directly from the run's result files; nothing is typed by hand.