Paul Lin

Evolutionary Attribution Graph Pruner

AI, Research | 2025

An evolutionary algorithm for pruning attribution graphs in LLMs, built as the final project for CSE 848: Computational Evolution, a graduate course at Michigan State University. I worked on it with Uzair Mohammed, a friend from AI Club.

Background

Around the beginning of that semester, I became interested in AI interpretability. Uzair was already experienced with the topic and had multiple ongoing research projects. When the professors announced that the final project would be open-ended and related to computational evolution, I wanted to find a way to apply it to an interpretability problem so we could work on it together.

Process

Attribution graphs are currently one of the clearest ways to explain the relationship between a model's inputs and outputs. They show which nodes and layers had the biggest influence on a result. To produce one, the entire model is loaded and the graph is greedily pruned to show where that influence occurred.

Our algorithm takes that graph and uses a multi-objective evolutionary algorithm to simplify the pruning process.

Outcome

The result is a cleaner attribution graph that makes it easier to distinguish which nodes matter.

Full report on Google Drive.