Equation 5 · Part 2 · The Hardest Unsolved Problems in Mechanistic Interpretability
Symbol j
What this part means
j appears in the bound of this sum. The bound states where the repeated operation starts, ends, or which values it includes.
Its job in the formula
j appears in the bound of this sum. The bound states where the repeated operation starts, ends, or which values it includes.
Full expression→Symbol j→Article meaning
The passage around this formula
Leask, Nanda and colleagues then tested the assumption directly with two new techniques, and the result undercuts the idea that there is a “right” dictionary size waiting to be found by scaling further. Stitching the dictionaries of differently sized sparse autoencoders together, they show that larger dictionaries recover latents genuinely missing from smaller ones — the smaller dictionary is incomplete. Training a second, “meta” sparse autoencoder on the decoder directions of a first one, they show that what looks like a single, atomic feature in a large dictionary is itself well approximated by a sparse combination of directions from a smaller one — a reported example decomposes an…
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A variable is a named place for a value. Its letter is a local label: x can mean position in one formula and a data point in another.
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Sources cited in the surrounding passage
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