Equation 15 · Part 1 · Measuring What a RAG System Retrieves, Not Just What It Answers
Symbol k
What this part means
the scored by recall at.
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
A set of queries paired with the identifiers of the passages that answer them, scored by recall at k and nDCG, survives every later change to the generator, the prompt template, or the model vendor, because none of those changes touch the object being scored.
The passage around this formula
The practical consequence is that a retrieval-only evaluation is cheap to build once and reusable forever. A set of queries paired with the identifiers of the passages that answer them, scored by recall at k and nDCG, survives every later change to the generator, the prompt template, or the model vendor, because none of those changes touch the object being scored.
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.
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Sources cited in the article section
- [3] The TREC-8 Question Answering Track Report ↗
- [2] BEIR: A Heterogeneous Benchmark for Zero-shot Evaluation of Information Retrieval Models ↗
These citations provide research context; check each source for the exact claim it supports.