Addressing the need to find relevant information buried in a pile of documents, the article discusses the importance of assigning relevance scores to documents based on search queries.
Introduces the concept of tokens in documents and the creation of an inverted index to associate tokens with the documents they appear in.
Explains the initial scoring algorithm based on token frequency in documents, highlighting the need to address issues such as token count and relevancy.
Proposes an enhanced scoring function considering all query tokens, limiting the impact of individual tokens, and boosting results matching multiple tokens.
Introduces the concept of diminishing returns to prevent a linear score increase based on token frequency, providing a more nuanced scoring approach.
Discusses the limitations of the TF approach and introduces the TF-IDF method to incorporate the rarity of words across all documents in the score calculation.
Further advances the scoring algorithm by introducing the BM25 method, which considers factors like term frequency, document length, and normalization to determine document relevance.
Detailed examples and calculations are provided to demonstrate how BM25 scoring works and how it can be implemented effectively in code.
The article concludes by highlighting the importance of adapting the scoring algorithm to consider various document attributes like title, date, and location for improved relevance ranking.