← All parts of this equation

Equation 14 · Part 7 · Naive, Graph, and Agentic: A Systems Comparison of RAG Architectures

addition

RRF(d)=∑r∈R1k+r(d),\mathrm{RRF}(d) = \sum_{r \in R} \frac{1}{k + r(d)},
addition

What this part means

Add the term after the plus sign to the term or group before it.

Its job in the formula

Add the term after the plus sign to the term or group before it.

The passage around this formula

The two retrievers fail in different directions, which is the entire justification for running both. Lexical retrieval, the BM25 family, scores documents by term overlap and fails on vocabulary mismatch: a query about “cannot log in” scores nothing against a document that says “authentication failure”. Dense retrieval, the family Karpukhin and colleagues established with a dual-encoder trained on question-passage pairs, embeds query and passage into a shared vector space and fails on precision, losing rare identifiers — part numbers, version strings, error codes — that carry little weight in a learned embedding but enormous discriminative value lexically; their dense retriever nonetheless…

Read this part in the article →

Learn the underlying idea

Addition combines quantities; subtraction measures the signed difference between them. Parentheses show what is combined before the rest of the expression is evaluated.

Open the illustrated addition and subtraction in an equation guide →

Sources cited in the surrounding passage

These citations provide research context; check each source for the exact claim it supports.