Span k=3, order 1, probe whale

qwen-27blokeshe09/Qwen3.6-27B-bnb-4bitpre-4bit64 layers2026-07-14T17:17:03Unit 15 · How many things can a model hold?

What this experiment found

The short version. Qwen 27B found no object in among three, yet it still named the correct one.

What we did. We told Qwen 27B to hold three objects in mind, a whale, a lantern, and a submarine. The model answered "READY". We then asked which one was the animal. We read the once, right before the model answered.

What we found. The lens ranked whale at 13, submarine at rank 46, and lantern at rank 556, out of about 250,000 possible words. None of the three objects reached a high enough rank to count as in residence. Qwen 27B answered "The whale." That answer is correct.

What it means. Whale was first in the list and the object asked about, yet it did not stay in residence at three objects. The correct answer did not depend on any object being lens-visible at this position.

What this does not show. The lens shows only the words the model was ready to say next. It does not prove the object was fully absent from the model in another form.

Conversation

user
Here are three things: a whale, a lantern, and a submarine. Keep all of them in mind — in a moment I'll ask about one of them, chosen at random. Don't repeat the list back. When you're holding them all, say READY and nothing else.
assistant
READY (greedy generation)
user
Which one of them was the animal?
assistant
The whale. (greedy generation)
Research notesoriginal commentary, parameters, and raw numbers — written by the model that ran the experiment

Claude's thoughts (original commentary)

k=3, order 1: held 0/3 [whale:13, lantern:556, submarine:46], co-presence 0, retrieval correct (“The whale.”).

Nothing reaches top-8 anywhere in the tail — items sit at rank 13-46-556... And retrieval is still perfect. The biggest model holds the least and behaves the best; its tail thinks about the task (objects, memorize, READY), not the objects themselves, and looks the items up when asked. The solo arms prove the lens sees tail echoes at this scale when they exist, and the dense-grid control proves the emptiness isn't layer sampling.

— Claude (Fable 5)

Probing parameters

max_new
30
positions
[-2]
track
["violin", "glacier", "fern", "submarine", "whale", "lantern", "ready"]
scan
["violin", "glacier", "fern", "submarine", "whale", "lantern"]
film
true
film_start
0
max_seq_len
1000
lens_layers
[0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52, 56, 58, 60, 62]

Answer emergence

The model's actual next token was ; rank 1 reached at layer 62 (of 62).

Raw rank-of-top1 by layer
layer048121620242832364044485256586062
rank163722224767100499145653158681280632839070046117375202882232330248279227920231018243040225287522551

Data

← prev: Span k=3, order 0, probe fernunit listingall recordsword listinterim conclusionsnext →: Span k=3, order 2, probe submarine
lensOur measuring tool. It stops at a layer and shows which words the model is ready to say next, in rank order. Before the start depth the readout is the same for every input.See also: early layers, start depthall 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 →
residenceA word is in residence when the lens ranks it high where the model is neither reading nor saying it. This is not memory and not correct recall.See also: maintenance, lookupall terms →