Similarity Scoring

Antoni Kozelski
CEO & Co-founder
July 3, 2025
Glossary Category
RAG

Similarity Scoring is a computational method that quantifies the degree of similarity between data points, typically vectors, using mathematical distance metrics or similarity functions. Common similarity scoring methods include cosine similarity, which measures the angle between vectors regardless of magnitude; Euclidean distance, which calculates straight-line distance in vector space; and dot product, which considers both direction and magnitude. These scores range from 0 to 1 (or -1 to 1 for cosine similarity), where higher values indicate greater similarity. Similarity scoring is fundamental to vector databases, recommendation systems, semantic search, and clustering algorithms. The choice of scoring method depends on data characteristics and application requirements: cosine similarity excels for text embeddings and high-dimensional sparse data, while Euclidean distance works well for dense numerical data. Advanced techniques include learned similarity functions and context-aware scoring that adapts to specific domains or user preferences.