The fastest useful citation check is to isolate one important claim and compare it with the supporting passage. Ask whether the source supports the same subject, time period and measurement—not merely whether its title concerns the same topic.
A 2023 study of Bing Chat, NeevaAI, Perplexity and YouChat reported that 51.5% of generated sentences were fully supported by citations, while 74.5% of citations supported the associated sentence. These were study-wide results for the systems and test used then, not a score for today’s Perplexity.[1]
Three sentences that use the same paper differently
Illustrative claim audit
| Proposed sentence | Assessment | Reason |
|---|---|---|
| The 2023 evaluation found 51.5% of sentences fully supported by citations. | Supported with the study scope attached | Keeps the date, unit and evaluated setting |
| Half of Perplexity’s answers in 2026 are wrong. | Unsupported | Changes the system scope, year, unit and meaning of citation support |
| The study found 74.5% of whole answers correct. | Unsupported | Turns a citation-level support measure into answer-level correctness |
The second sentence is not repaired by adding the paper’s link. Its problem is the inference. A missing citation can sometimes be fixed by finding the supporting passage; a changed denominator or invented present-day score requires changing the sentence.
Coverage and precision answer different questions
Citation coverage asks how much of the answer is supported. Citation precision asks whether the references actually justify the claims to which they are attached. An answer can cite one statement well while leaving its most important conclusion unsupported. It can also attach many weakly relevant links to a sentence without improving that sentence’s evidential basis.
For a purchasing comparison, separate price, availability and performance into distinct claims. A pricing page can support the first, a dated release notice the second, and an appropriate test the third. Reusing one reference for all three makes the answer look sourced without doing the work.
A compact check for a consequential answer
Copy the decisive sentence. Open the cited source and locate the passage. Record the source date and the population or product version it describes. Then mark the sentence supported, partly supported or unsupported, with one specific reason. This produces a useful correction request rather than a vague instruction to “fact-check everything”.
Keep the supporting passage with the corrected sentence. The final improvement is not a larger bibliography; it is a claim that a reader can verify without guessing which part of the source the writer relied on.
Sources & further reading
- Evaluating Verifiability in Generative Search Engines Liu, Zhang and Liang; arXiv / EMNLP 2023 · 19 Apr 2023 · Accessed 14 Oct 2026