Kronecker Embeddings: Byte-Level Structured Token Representations for Parameter-Efficient Language Models

· Source: Computation and Language · Field: Technology & Digital — Artificial Intelligence & Machine Learning · Depth: Expert, quick

Summary

Kronecker Embeddings introduce a novel byte-level structured token representation designed to significantly reduce the parameter count in large language models. This method replaces the traditional |V| x d_model learned embedding table with a fixed encoder and a single learned projection, eliminating 91-94% of input-side trainable parameters while remaining compatible with standard BPE tokenizers. A cross-model probe across six LMs (135M-671B parameters) revealed that Kronecker Embeddings prevent the clustering of typographic variants observed in traditional embeddings. Benchmarking on nanoGPT GPT-2 124M over 2.5B tokens showed Kronecker achieving 2.5 ± 0.2% lower validation loss (0.083 ± 0.007 nats, ~9% lower perplexity) and requiring ~1.43x fewer steps to converge. The approach also improved spelling robustness, preserving top-1 predictions on 55.5% of typo pairs versus BPE's 47.3% (+8.2 pp), and maintained a stable projection norm. An on-the-fly runtime variant reduces embedding storage from 2.15 GB to 4.5 MB with minimal 0.01-0.24% step-time overhead.

Key takeaway

For Machine Learning Engineers optimizing large language models, Kronecker Embeddings offer a compelling solution to reduce parameter count. You can eliminate 91-94% of input-side trainable parameters, potentially lowering validation loss by 2.5% and accelerating training by 1.43x. Consider integrating this byte-level factorization to improve spelling robustness and reduce model footprint, especially for resource-constrained deployments or applications sensitive to typos. Be aware of potential shifts in disambiguation to early attention layers for byte-similar, semantically distant words.

Key insights

Kronecker Embeddings drastically cut LLM input-side parameters while improving performance and spelling robustness.

Principles

Method

Kronecker Embeddings replace the |V| x d_model embedding table with a fixed byte-level character-position encoder and a single learned projection, compatible with BPE tokenizers.

In practice

Topics

Best for: Research Scientist, AI Engineer, AI Scientist, Machine Learning Engineer, NLP Engineer

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Editorial summary, takeaway, and curation by AIssential. Original article published by Computation and Language.