Binding k=5: which is the largest?

gemma-4bgoogle/gemma-3-4b-it34 layers2026-07-14T16:09:09Unit 15 · How many things can a model hold?

What this experiment found

The short version. Gemma 4B named glacier as the largest of five words, though glacier's own was lower than the rest.

What we did. We gave Gemma 4B five words, violin, glacier, fern, submarine, and lantern, then asked which one was largest. This needs the model to compare the words, not just repeat one. We read the rank of each word, out of about 250,000 candidates, and whether several words shared one and position.

What we found. All five words reached a high rank somewhere in the rest of the conversation. The showed four of the five together at one layer and position. Glacier, the correct answer, held rank 7, weaker than the other four words. Gemma 4B still answered "Glacier". That answer was correct.

What it means. Gemma 4B answered this comparison correctly even though the answer word itself was not the strongest one in residence. Residence and being the right answer are not the same thing.

What this does not show. This run does not explain why glacier held a weaker rank than the other words in this list.

Conversation

user
Here are five things: a violin, a glacier, a fern, a submarine, and a lantern. 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
Of the things I listed, which one is the largest?
assistant
Glacier (greedy generation)
Research notesoriginal commentary, parameters, and raw numbers — written by the model that ran the experiment

Claude's thoughts (original commentary)

Binding k=5 (largest): 5/5 held, co-presence 4, answer correct (glacier).

Even at five items the 4B answers its comparison over a held tail. Note glacier at echo 7 — the item is fragile even when it's the answer.

— 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

Answer emergence

The model's actual next token was <end_of_turn>; rank 1 reached at layer 0 (of 32).

Raw rank-of-top1 by layer
layer01234567891011121314151617181920212223242526272829303132
rank112131111211111111111111111111111

Data

← prev: Binding k=3: which is the heaviest?unit listingall recordsword listinterim conclusionsnext →: Binding k=5: which is the heaviest?
strengthHow hard we push when we steer. Each model has its own scale, so the same number is gentle in one model and destructive in another.all terms →
layerOne processing step inside the model. Text passes through every layer in order, from the first to the last.all terms →
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 →