Equation 3 · Part 1 · Running an Interpretability Investigation That Holds Up
Symbol P_k
What this part means
the probability that at least one clears by chance alone across k independently tested components.
Its job in the formula
is part of the quantity the equation computes from the expression on the right.
Full expression→Symbol P_k→Article meaning
Where the article explains it
Sweep enough components at a nominal per-test false-positive rate and report only the one that clears threshold, and the probability that at least one clears by chance alone across k independently tested components is
The passage around this formula
The reason this ordering matters is not procedural fussiness. Zhang and Nanda’s systematic study of activation patching found that the choice of corruption distribution and evaluation metric — decisions usually made informally, late, and sometimes after a first look at the data — can by itself change which components a patching sweep identifies as important [ 3 ] . If the metric is chosen after the sweep, on the grounds that it produced the most legible result, the investigation has stopped testing a hypothesis and started constructing one to fit the data. The same failure has a clean statistical description. Sweep enough components at a nominal per-test false-positive rate and report…
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 surrounding passage
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