Equation 28 · Part 1 · Probing, Sparse Autoencoders, Patching, and Steering: The Main Interpretability Methods, Compared
Symbol h_ell
What this part means
the residual-stream activation at layer .
Its job in the formula
ll is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.
Full expression→Symbol h_ell→Article meaning
Where the article explains it
where P and N index matched positive and negative examples of the target behaviour, is the residual-stream activation at layer , and is a coefficient the operator sets by hand.
The passage around this formula
where P and N index matched positive and negative examples of the target behaviour, is the residual-stream activation at layer , and is a coefficient the operator sets by hand. Nothing in this construction requires understanding why the network represents the concept along this direction, only that adding it produces the intended behavioural shift.
Learn the underlying idea
A subscript is a label attached below a symbol. It often selects a time step, component, category, or member of a sequence.
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Sources cited in the article section
- [12] Representation Engineering: A Top-Down Approach to AI Transparency ↗
- [13] Steering Language Models With Activation Engineering ↗
- [14] Steering Llama 2 via Contrastive Activation Addition ↗
- [15] Analyzing the Generalization and Reliability of Steering Vectors ↗
These citations provide research context; check each source for the exact claim it supports.