Why most deep-research reports cannot be audited.
A deep-research tool searches the web, reads pages and writes a report with citations. What reaches you is the prose and a list of links. The run that produced it is not kept: which searches were made, which pages were actually read, which passage a sentence rests on, and what the tool looked for and did not find. A reader who wants to check one sentence has to redo the research.
When independent researchers did redo it, the gap was large. DeepTRACE, an audit of deep-research systems, reports citation accuracy ranging from 40 to 80 percent across the systems it tested. Cited but Not Verified found that the strongest models’ cited reports reach only 39 to 77 percent factual accuracy once each citation is checked against its source.arXiv:2509.04499 · arXiv:2605.06635
the five questions a reader asks and where each one dead-ends: the problem