Equation 15 · Retrieval Is an Evidence System, Not a Memory
What does this equation mean?
Read the formula alongside the article passage below. Each part has a deeper page with its role in the equation, the supporting passage and nearby citations.
This mathematical expression combines the displayed quantities; its precise role follows from the surrounding article text. Read the equation part by part below; each part has a contextual explanation and a link to its mathematical background.
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Symbol k
k is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.
How to interpret it
Read this expression with the definitions, units, and assumptions supplied by the article.
What the article says around this equation
Read together, these say something specific about the top- k parameter. Increasing k raises the probability that the answer is present and simultaneously raises the volume of distractors and the chance that the answer sits mid-block. Recall and usability move in opposite directions, so k has an interior optimum that must be measured rather than assumed, and the optimum is corpus-specific.
Sources cited in the article section
- [11] Lost in the Middle: How Language Models Use Long Contexts ↗
- [12] Large Language Models Can Be Easily Distracted by Irrelevant Context ↗
- [18] Benchmarking Large Language Models in Retrieval-Augmented Generation ↗
These citations give research context. Read each source to check which claims it supports.