Structure Retention in Embedding Spaces as a Predictor of Benchmark Performance
This study investigates the relationship between the performance of embedding models and the structural properties of their embedding spaces, with the aim of predicting downstream task effectiveness. Leveraging the MTEB benchmark, the authors evaluate 25 prominent embedding models across five tasks in both English and multilingual settings. They characterize the local and linear structures of embedding spaces using nearest-neighbor overlap and independent component analysis (ICA). The work reveals, for the first time, a remarkably high correlation (up to 0.97) between the degree of local structure preservation in embedding spaces and model performance on downstream tasks. Furthermore, it demonstrates that different tasks exhibit distinct dependencies on local versus linear structural information. These findings indicate that structural characteristics of embedding spaces can effectively predict model performance across diverse tasks, including retrieval, bilingual text mining, pair classification, and summarization.