Methods · Training Data Attribution

Kronecker-Factored Approximate Curvature (K-FAC)

Survey sections: §11.2.3 Kronecker-Factored Approximate Curvature (K-FAC)

Martens & Grosse (2015) proposed Kronecker-Factored Approximate Curvature (K-FAC) to approximate a large Fisher information matrix (FIM) using a set of smaller matrices.

Assumptions and requirements

Although K-FAC approximates the FIM rather than the GGN, these matrices are equivalent for common loss functions under suitable probabilistic assumptions.
The approximation separates the expectation into two independent factors: activations and pseudo-gradients.

Intended applications

G. This shows that we can use K-FAC to approximate the GGN used in the PBRF influence score.

Related methods

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Key papers

Cited in §11.2.3.

Also discussed in: §11.2.3 Addressing the Computational and Memory Bottlenecks of GGN · §11.2.3 Eigenvalue-Corrected K-FAC (EK-FAC) and ASTRA

Other methods in Training Data Attribution

Verbatim Data Attribution: OLMoTrace · Influence Functions (Gradient-Based Attribution) · Eigenvalue-Corrected K-FAC (EK-FAC) and ASTRA · TRAK (Tracing with the Randomly-projected After Kernel) · TracIn