Equation 8 · Part 1 · Measuring What a RAG System Retrieves, Not Just What It Answers
Symbol q
What this part means
q is a part of this expression. Its role is fixed by the surrounding article and by the operations shown in the formula.
Its job in the formula
q 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 q→Article meaning
The passage around this formula
averaged over a query set Q , where is the position of the first relevant result for query q . Mean reciprocal rank was formalised as the primary scoring metric for the TREC-8 Question Answering track, the first large-scale evaluation of domain-independent question answering systems, where it assigned a value of 1/r to a ranked list of candidate answers based on the rank r of the one judged correct [ 3 ] . It rewards getting the single most useful passage near the top and is blind to everything else in the list, which is exactly the property a downstream generator that reads only the first few passages needs measured.
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 surrounding passage
These citations provide research context; check each source for the exact claim it supports.