LONG-CONTEXT EVALUATION IN LANGUAGE MODELS

Summary from the TLDR AI newsletter

This study identifies a key flaw in using perplexity (PPL) to evaluate LLMs' long-context capabilities - PPL averages across all tokens and misses crucial ones needed for understanding extended inputs. To improve this, the authors introduce LongPPL, a metric that highlights these essential tokens for a clearer measure of long-context performance.