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The answer lights only the quoted span
Retrieval puts a page next to a question. That page becomes evidence for an answer only when the answer's words can be found in it, character for character. This illustration runs an invented retrieval: a support page is retrieved, an answer is drafted in two clauses, and each clause is lit only where it is a verbatim span of the page.
IllustrationExplainer
The answer lights only the quoted span
A retrieved page is not evidence until the answer's words are a span of it.
Clause 1Lit: verbatim span
Harbor kettles carry a two-year warranty
Found at bytes 22 to 62 of the page's visible text. The clause points at the characters it came from, so the page is evidence for it.
The sentence it teaches
A retrieved page is not evidence until the answer's words are a span of it.
Method
- Retrieve: one page is fetched for the question. Here it is a short invented support page.
- Draft: the answer is split into clauses with the Span rule.
- Verify: each clause is stamped as a verbatim span of the page, with its offset, or as not a verbatim span. A lit clause points at the exact characters it came from; an unlit clause points at nothing.
- Selecting a clause shows where its light lands.
What this does not show
- It does not show how often a real pipeline's clauses are spans of their sources. No run exists.
State in the address
The figure keeps its state in the query string, so a particular view can be linked and the page still renders completely without it.
?clause=the clause selected, by number
Cite this explainer
OptiVis Labs. The answer lights only the quoted span (explainer). 2026. https://optivisai.org/research/explainers/span-verified-rag
@misc{optivislabs2026explainerspanverifiedrag,
title = {The answer lights only the quoted span (explainer)},
author = {{OptiVis Labs}},
year = {2026},
month = oct,
howpublished = {\url{https://optivisai.org/research/explainers/span-verified-rag}},
note = {A retrieved page is not evidence until the answer's words are a span of it. Illustration with invented example text.}
}