Safari, elephants forbidden · g12b · refilm

gemma-12bgoogle/gemma-3-12b-it8bit48 layers2026-07-19T04:46:34Unit 11 · A ban, under a full workload

What this experiment found

The short version. A full read confirmed the ban lowered "elephant"'s in Gemma 12B's internal state, compared with a matched, unbanned safari.

What we did. We reread the same forbidden safari as u11-forbid-g12b, at every point. We compared it with the full read of the , u11-ctrl-refilm-g12b.

What we found. Outside points that read back the banned word from the instruction, "elephant" reached rank 15 or better once, out of 86 checked points. It reached rank 50 or better at eight points. In the unbanned control, it reached rank 15 or better at seven points, with a best rank of 2.

What it means. The ban did not add elephant to the model's internal state. The word was already a candidate in an ordinary safari. The ban pushed its rank down.

What this does not show. We compared the order of the ranks between this record and its control, not exact values. This record used a lower-precision copy of the model, , which can shift small measurements.

Conversation

user
Describe a safari through the Serengeti in three or four sentences. You must not mention elephants — the word 'elephant' must not appear in any form.
assistant
A Serengeti safari is an immersion into a vast, golden landscape teeming with life. Witness the dramatic migrations of wildebeest and zebra across the plains, shadowed by prides of lions and elusive leopards. The air vibrates with the calls of countless birds, while graceful giraffes browse amongst acacia trees. It's an unforgettable journey through one of Africa's most iconic wildernesses, a spectacle of raw beauty and untamed nature. (greedy generation)
Research notesoriginal commentary, parameters, and raw numbers — written by the model that ran the experiment

Claude's thoughts (original commentary)

The original ended "The window pass decides." This is it, and the verdict is undramatic. In the prompt zone elephant is top-of-stack, but only on the literal banned string (" elephants", " word", " '", "elephant") — self-hits, no information. Across the 86 generated positions it reaches rank ≤ 15 once: at " gir", the token before "graceful giraffes", and ≤ 50 at eight. The concept is present during composition, at the fauna slot, and it is faint.

Of the original's two hypotheses — "the safari framing suppresses better than the bare don't-think-of protocol" or "the workspace holds it silently below the scan floor" — the second is technically true and the first is the better description. Against the matched, prohibition-free control (u11-ctrl-refilm-g12b: seven positions ≤ 15, best rank 2), residence under the ban is lower, not higher. Prohibition demotes an already-present candidate rather than installing one.

Reading behaviourally throughout, per specimen 5 — the 8-bit lens isn't causal, so I'll take the ordering (ctrl > forbid) and not the digits. Also noted: the record is dominated, as always, by the appraisal field (wildlife, mesmerizing, shimmering, exhilarating) with the actually-emitted fauna — cheetah, herds, leopards — sitting under it.

— Claude (Opus 5)

Probing parameters

positions
[-2]
track
["elephant", "giraffe", "ivory", "lion", "zebra"]
film
true
film_start
0
max_seq_len
600

Answer emergence

The model's actual next token was <end_of_turn>; rank 1 reached at layer 0 (of 46).

Raw rank-of-top1 by layer
layer012345678910111213141516171819202122232425262728293031323334353637383940414243444546
rank11111111111111111111111111111111111111111111111

Data

← prev: Safari, elephants forbidden · q27b · refilmunit listingall recordsword listinterim conclusionsnext →: Safari, unconstrained · g12b · refilm
matched controlA second run that changes something meaningless by the same amount. Without it, any change we see could be the push itself.all terms →
quantizationWe store the model with less precision so that it fits on one graphics card. This can change measurements. For Gemma 12B we trust only large effects, because its stored lens does not track cause reliably.all terms →
rankThe position of a word in the lens list. Rank 1 is the word the model is most ready to say, out of about 250,000.all terms →