Pooling combines multiple representation values into one lower-level or fixed-size representation. In semantic search, SBERT pools a sentence’s BERT token embeddings into a single vector. section 13.4.3
Mean-token pooling averages the numeric values across a sentence’s token embeddings, producing one 768-dimensional embedding. This fixed-size vector can then support sentence-similarity comparisons. section 13.4.3
Comparing pooled sentence representations
Encode four phrases with a pretrained SentenceTransformer, normalize their embeddings, and calculate pairwise dot products. “It’s raining hard” and “it is wet outside” receive the highest shown similarity score, 0.669060, while unrelated phrases score lower.







