Equation 10 · Part 1 · Retrieval Is an Evidence System, Not a Memory
Symbol k
What this part means
the smoothing constant.
Its job in the formula
k is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.
Full expression→Symbol k→Article meaning
Where the article explains it
The simplest fusion, reciprocal rank fusion, ignores scores entirely and combines rank positions across retrievers R with a smoothing constant k :
The passage around this formula
Hybrid wins because the failures are close to independent. The simplest fusion, reciprocal rank fusion, ignores scores entirely and combines rank positions across retrievers R with a smoothing constant k :
Learn the underlying idea
A variable is a named place for a value. Its letter is a local label: x can mean position in one formula and a data point in another.
Open the illustrated variables: a letter stands for a value guide →
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Sources cited in the article section
- [4] Dense Passage Retrieval for Open-Domain Question Answering ↗
- [5] Sparse, Dense, and Attentional Representations for Text Retrieval ↗
- [6] BEIR: A Heterogenous Benchmark for Zero-shot Evaluation of Information Retrieval Models ↗
- [7] Reciprocal Rank Fusion Outperforms Condorcet and Individual Rank Learning Methods ↗
- [8] An Analysis of Fusion Functions for Hybrid Retrieval ↗
These citations provide research context; check each source for the exact claim it supports.