Probing Without Labels

Contrast-only Reproductions of Interpretability Results

Stefan F. Schouten, Peter Bloem · Vrije Universiteit Amsterdam · BlackboxNLP 2026

Negation and truth

Four statements per city: affirmed or negated, with the correct or an incorrect country. On the first three components the four statement types form a tetrahedron. Drag to rotate; the buttons look down the axis that collapses one contrast.

Llama-2-7B · w-tcPCA

Llama-2-7B · tcPCA

Llama-3.1-8B · w-tcPCA

Llama-3.1-8B · tcPCA

True, false, neither

Statements about real cities (true or false) and invented ones (neither), on the first two components.

Llama-2-7B · w-tcPCA

Llama-2-7B · tcPCA

Llama-3.1-8B · w-tcPCA

Llama-3.1-8B · tcPCA

Days of the week

Tuples that differ only in the weekday; the class means are joined in calendar order.

Llama-2-7B · w-tcPCA

Llama-2-7B · tcPCA

Llama-3.1-8B · w-tcPCA

Llama-3.1-8B · tcPCA

Months of the year

Tuples that differ only in the month.

Llama-2-7B · w-tcPCA

Llama-2-7B · tcPCA

Llama-3.1-8B · w-tcPCA

Llama-3.1-8B · tcPCA